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Sample records for 99mtechnetium-mibi single photon

  1. Indistinguishability of independent single photons

    NASA Astrophysics Data System (ADS)

    Sun, F. W.; Wong, C. W.

    2009-01-01

    The indistinguishability of independent single photons is presented by decomposing the single photon pulse into the mixed state of different transform-limited pulses. The entanglement between single photons and outer environment or other photons induces the distribution of the center frequencies of those transform-limited pulses and makes photons distinguishable. Only the single photons with the same transform-limited form are indistinguishable. In details, the indistinguishability of single photons from the solid-state quantum emitter and spontaneous parametric down-conversion is examined with two-photon Hong-Ou-Mandel interferometer. Moreover, experimental methods to enhance the indistinguishability are discussed, where the usage of spectral filter is highlighted.

  2. Single-photon quadratic optomechanics

    PubMed Central

    Liao, Jie-Qiao; Nori, Franco

    2014-01-01

    We present exact analytical solutions to study the coherent interaction between a single photon and the mechanical motion of a membrane in quadratic optomechanics. We consider single-photon emission and scattering when the photon is initially inside the cavity and in the fields outside the cavity, respectively. Using our solutions, we calculate the single-photon emission and scattering spectra, and find relations between the spectral features and the system's inherent parameters, such as: the optomechanical coupling strength, the mechanical frequency, and the cavity-field decay rate. In particular, we clarify the conditions for the phonon sidebands to be visible. We also study the photon-phonon entanglement for the long-time emission and scattering states. The linear entropy is employed to characterize this entanglement by treating it as a bipartite one between a single mode of phonons and a single photon. PMID:25200128

  3. Nonlinear interaction between single photons.

    PubMed

    Guerreiro, T; Martin, A; Sanguinetti, B; Pelc, J S; Langrock, C; Fejer, M M; Gisin, N; Zbinden, H; Sangouard, N; Thew, R T

    2014-10-24

    Harnessing nonlinearities strong enough to allow single photons to interact with one another is not only a fascinating challenge but also central to numerous advanced applications in quantum information science. Here we report the nonlinear interaction between two single photons. Each photon is generated in independent parametric down-conversion sources. They are subsequently combined in a nonlinear waveguide where they are converted into a single photon of higher energy by the process of sum-frequency generation. Our approach results in the direct generation of photon triplets. More generally, it highlights the potential for quantum nonlinear optics with integrated devices and, as the photons are at telecom wavelengths, it opens the way towards novel applications in quantum communication such as device-independent quantum key distribution. PMID:25379916

  4. Single-photon decision maker

    PubMed Central

    Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    2015-01-01

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions. PMID:26278007

  5. Single-photon decision maker.

    PubMed

    Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    2015-01-01

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions. PMID:26278007

  6. Single-photon decision maker

    NASA Astrophysics Data System (ADS)

    Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    2015-08-01

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions.

  7. Spectral compression of single photons

    NASA Astrophysics Data System (ADS)

    Lavoie, J.; Donohue, J. M.; Wright, L. G.; Fedrizzi, A.; Resch, K. J.

    2013-05-01

    Photons are critical to quantum technologies because they can be used for virtually all quantum information tasks, for example, in quantum metrology, as the information carrier in photonic quantum computation, as a mediator in hybrid systems, and to establish long-distance networks. The physical characteristics of photons in these applications differ drastically; spectral bandwidths span 12 orders of magnitude from 50 THz (ref. 6) for quantum-optical coherence tomography to 50 Hz for certain quantum memories. Combining these technologies requires coherent interfaces that reversibly map centre frequencies and bandwidths of photons to avoid excessive loss. Here, we demonstrate bandwidth compression of single photons by a factor of 40 as well as tunability over a range 70 times that bandwidth via sum-frequency generation with chirped laser pulses. This constitutes a time-to-frequency interface for light capable of converting time-bin to colour entanglement, and enables ultrafast timing measurements. It is a step towards arbitrary waveform generation for single and entangled photons.

  8. Single photon searches at PEP

    SciTech Connect

    Hollebeek, R.

    1985-12-01

    The MAC and ASP searches for events with a single photon and no other observed particles are reviewed. New results on the number of neutrino generations and limits on selection, photino, squark and gluino masses from the ASP experiment are presented.

  9. Multi-photon absorption limits to heralded single photon sources

    PubMed Central

    Husko, Chad A.; Clark, Alex S.; Collins, Matthew J.; De Rossi, Alfredo; Combrié, Sylvain; Lehoucq, Gaëlle; Rey, Isabella H.; Krauss, Thomas F.; Xiong, Chunle; Eggleton, Benjamin J.

    2013-01-01

    Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g(2)(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources. PMID:24186400

  10. Single photons from dissipation in coupled cavities

    NASA Astrophysics Data System (ADS)

    Flayac, H.; Savona, V.

    2016-07-01

    We propose a single-photon source based on a pair of weakly nonlinear optical cavities subject to a one-directional dissipative coupling. When both cavities are driven by mutually coherent fields, sub-Poissonian light is generated in the target cavity even when the nonlinear energy per photon is much smaller than the dissipation rate. The sub-Poissonian character of the field holds over a delay measured by the inverse photon lifetime, as in the conventional photon blockade, thus allowing single-photon emission under pulsed excitation. We discuss a possible implementation of the dissipative coupling relevant to photonic platforms.

  11. Improved photon counting efficiency calibration using superconducting single photon detectors

    NASA Astrophysics Data System (ADS)

    Gan, Haiyong; Xu, Nan; Li, Jianwei; Sun, Ruoduan; Feng, Guojin; Wang, Yanfei; Ma, Chong; Lin, Yandong; Zhang, Labao; Kang, Lin; Chen, Jian; Wu, Peiheng

    2015-10-01

    The quantum efficiency of photon counters can be measured with standard uncertainty below 1% level using correlated photon pairs generated through spontaneous parametric down-conversion process. Normally a laser in UV, blue or green wavelength range with sufficient photon energy is applied to produce energy and momentum conserved photon pairs in two channels with desired wavelengths for calibration. One channel is used as the heralding trigger, and the other is used for the calibration of the detector under test. A superconducting nanowire single photon detector with advantages such as high photon counting speed (<20 MHz), low dark count rate (<50 counts per second), and wideband responsivity (UV to near infrared) is used as the trigger detector, enabling correlated photons calibration capabilities into shortwave visible range. For a 355nm single longitudinal mode pump laser, when a superconducting nanowire single photon detector is used as the trigger detector at 1064nm and 1560nm in the near infrared range, the photon counting efficiency calibration capabilities can be realized at 532nm and 460nm. The quantum efficiency measurement on photon counters such as photomultiplier tubes and avalanche photodiodes can be then further extended in a wide wavelength range (e.g. 400-1000nm) using a flat spectral photon flux source to meet the calibration demands in cutting edge low light applications such as time resolved fluorescence and nonlinear optical spectroscopy, super resolution microscopy, deep space observation, and so on.

  12. Single photon emission computed tomography

    SciTech Connect

    Piez, C.W. Jr.; Holman, B.L.

    1985-07-01

    Single photon emission computed tomography (SPECT) is becoming an increasingly important part of routine clinical nuclear medicine. By providing tomographic reconstructions in multiple planes through the patient, SPECT expands the clinical applications in nuclear medicine as well as providing better contrast, edge definition and separation of target from background activities. Imaging techniques have been developed for the evaluation of regional cerebral blood flow using radiolabeled amines. Thus, cerebral functional imaging can be used in the diagnosis of acute cerebral infarction, cerebral vascular disease, dementia and epilepsy. SPECT plays a complementary role in the evaluation of coronary artery disease, particularly when it is coupled with thallium-201 and exercise testing. SPECT extends our diagnostic capabilities in additional areas, such as liver and bone scintigraphy as well as tumor imaging with gallium-67.

  13. Single-photon detection, truth, and misinterpretation

    NASA Astrophysics Data System (ADS)

    Berloffa, E. H.

    2013-10-01

    Within this investigation it is critically questioned, if we really can detect "single photons", respectively the response of a single quantum transition by use of modern photon detectors. In the course it is shown that avalanche photodiodes (AVDs) especially in the "Geiger" mode by virtue of its geometry (effective area) indeed can detect "single photon" events as proclaimed by the manufacturers, but they tacitly assume the bandwidth of originating visible source being not greater than ~ 2.107 [Hz]. A short excurse to solid state basic physics makes it obvious applying the adequate doping accomplishes "single photon detection". Nevertheless this does not mean there is a 1:1 correspondence between a photon emanated from the source location and that detected within the detector module. Propagation characteristics were simply overlooked during the numerous discussions about "single photon" detection. Practical examples are worked out on hand of a pin- / and a AVDphotodiode.

  14. Purification of single-photon entanglement.

    PubMed

    Salart, D; Landry, O; Sangouard, N; Gisin, N; Herrmann, H; Sanguinetti, B; Simon, C; Sohler, W; Thew, R T; Thomas, A; Zbinden, H

    2010-05-01

    Single-photon entanglement is a simple form of entanglement that exists between two spatial modes sharing a single photon. Despite its elementary form, it provides a resource as useful as polarization-entangled photons and it can be used for quantum teleportation and entanglement swapping operations. Here, we report the first experiment where single-photon entanglement is purified with a simple linear-optics based protocol. In addition to its conceptual interest, this result might find applications in long distance quantum communication based on quantum repeaters. PMID:20482160

  15. Vision and the single photon (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Lakshminarayanan, Vasudevan

    2005-08-01

    The human visual system has an amazing sensitivity-even a single photon catch can trigger the release of a signal in a rod photoreceptor cell under certain circumstances. However, behaviorally it requires on an average 5-8 photons for a human to "see" a flash of light. This discrepancy is due to the intrinsic "dark noise" in the visual system. Various aspects of human visual sensitivity to single photons are reviewed and discussed.

  16. Single-photon emission tomography.

    PubMed

    Goffin, Karolien; van Laere, Koen

    2016-01-01

    Single-photon emission computed tomography (SPECT) is a functional nuclear imaging technique that allows visualization and quantification of different in vivo physiologic and pathologic features of brain neurobiology. It has been used for many years in diagnosis of several neurologic and psychiatric disorders. In this chapter, we discuss the current state-of-the-art of SPECT imaging of brain perfusion and dopamine transporter (DAT) imaging. Brain perfusion SPECT imaging plays an important role in the localization of the seizure onset zone in patients with refractory epilepsy. In cerebrovascular disease, it can be useful in determining the cerebrovascular reserve. After traumatic brain injury, SPECT has shown perfusion abnormalities despite normal morphology. In the context of organ donation, the diagnosis of brain death can be made with high accuracy. In neurodegeneration, while amyloid or (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) are the nuclear diagnostic tools of preference for early and differential diagnosis of dementia, perfusion SPECT imaging can be useful, albeit with slightly lower accuracy. SPECT imaging of the dopamine transporter system is widely available in Europe and Asia, but since recently also in the USA, and has been accepted as an important diagnostic tool in the early and differential diagnosis of parkinsonism in patients with unclear clinical features. The combination of perfusion SPECT (or FDG-PET) and DAT imaging provides differential diagnosis between idiopathic Parkinson's disease, Parkinson-plus syndromes, dementia with Lewy bodies, and essential tremor. PMID:27432669

  17. High purity bright single photon source.

    PubMed

    Neergaard-Nielsen, J S; Nielsen, B M; Takahashi, H; Vistnes, A I; Polzik, E S

    2007-06-25

    Using cavity-enhanced non-degenerate parametric down-conversion, we have built a frequency tunable source of heralded single photons with a narrow bandwidth of 8 MHz, making it compatible with atomic quantum memories. The photon state is 70% pure single photon as characterized by a tomographic measurement and reconstruction of the quantum state, revealing a clearly negative Wigner function. Furthermore, it has a spectral brightness of ~1,500 photons/s per MHz bandwidth, making it one of the brightest single photon sources available. We also investigate the correlation function of the down-converted fields using a combination of two very distinct detection methods; photon counting and homodyne measurement. PMID:19547121

  18. What are single photons good for?

    NASA Astrophysics Data System (ADS)

    Sangouard, Nicolas; Zbinden, Hugo

    2012-10-01

    In a long-held preconception, photons play a central role in present-day quantum technologies. But what are sources producing photons one by one good for precisely? Well, in opposition to what many suggest, we show that single-photon sources are not helpful for point to point quantum key distribution because faint laser pulses do the job comfortably. However, there is no doubt about the usefulness of sources producing single photons for future quantum technologies. In particular, we show how single-photon sources could become the seed of a revolution in the framework of quantum communication, making the security of quantum key distribution device-independent or extending quantum communication over many hundreds of kilometers. Hopefully, these promising applications will provide a guideline for researchers to develop more and more efficient sources, producing narrowband, pure and indistinguishable photons at appropriate wavelengths.

  19. Zero-Area Single-Photon Pulses.

    PubMed

    Costanzo, L S; Coelho, A S; Pellegrino, D; Mendes, M S; Acioli, L; Cassemiro, K N; Felinto, D; Zavatta, A; Bellini, M

    2016-01-15

    Broadband single photons are usually considered not to couple efficiently to atomic gases because of the large mismatch in bandwidth. Contrary to this intuitive picture, here we demonstrate that the interaction of ultrashort single photons with a dense resonant atomic sample deeply modifies the temporal shape of their wave packet mode without degrading their nonclassical character, and effectively generates zero-area single-photon pulses. This is a clear signature of strong transient coupling between single broadband (THz-level) light quanta and atoms, with intriguing fundamental implications and possible new applications to the storage of quantum information. PMID:26824539

  20. Heralding single photons without spectral factorability

    SciTech Connect

    Huang Yuping; Altepeter, Joseph B.; Kumar, Prem

    2010-10-15

    Recent efforts to produce single photons via heralding have relied on creating spectrally factorable two-photon states in order to achieve both high purity and high production rate. Through a careful multimode analysis, we find, however, that spectral factorability is not necessary. Utilizing single-mode detection, a similar or better performance can be achieved with nonfactorable states. This conclusion rides on the fact that even when using a broadband filter, a single-mode measurement can still be realized, as long as the coherence time of the triggering photons exceeds the measurement window of the on-off detector.

  1. Thermoelectric nanowire single-photon detector

    NASA Astrophysics Data System (ADS)

    Kuzanyan, Astghik A.; Kuzanyan, Armen S.

    2013-05-01

    We have collected and analyzed the values of thermoelectric parameters of thermoelectric materials and on this basis calculated the energy resolution and photon count rate of the Thermoelectric Nanowire Single-Photon Detector (TNSPD). It is concluded that the TNSPD can achieve higher specifications as compared with the best single-photon detectors. The lanthanum-cerium hexaboride sensors of TNSPD are expected to reach more than gigahertz count rates and will have a sensitivity of 0.1 eV. It means that the device is sensitive enough to register and spectrally characterize not only X-ray and UV, but also optical and infrared photons, as its major competitors, the superconducting and semiconducting single-photon detectors.

  2. Photon-efficient imaging with a single-photon camera

    NASA Astrophysics Data System (ADS)

    Shin, Dongeek; Xu, Feihu; Venkatraman, Dheera; Lussana, Rudi; Villa, Federica; Zappa, Franco; Goyal, Vivek K.; Wong, Franco N. C.; Shapiro, Jeffrey H.

    2016-06-01

    Reconstructing a scene's 3D structure and reflectivity accurately with an active imaging system operating in low-light-level conditions has wide-ranging applications, spanning biological imaging to remote sensing. Here we propose and experimentally demonstrate a depth and reflectivity imaging system with a single-photon camera that generates high-quality images from ~1 detected signal photon per pixel. Previous achievements of similar photon efficiency have been with conventional raster-scanning data collection using single-pixel photon counters capable of ~10-ps time tagging. In contrast, our camera's detector array requires highly parallelized time-to-digital conversions with photon time-tagging accuracy limited to ~ns. Thus, we develop an array-specific algorithm that converts coarsely time-binned photon detections to highly accurate scene depth and reflectivity by exploiting both the transverse smoothness and longitudinal sparsity of natural scenes. By overcoming the coarse time resolution of the array, our framework uniquely achieves high photon efficiency in a relatively short acquisition time.

  3. Photon-efficient imaging with a single-photon camera

    PubMed Central

    Shin, Dongeek; Xu, Feihu; Venkatraman, Dheera; Lussana, Rudi; Villa, Federica; Zappa, Franco; Goyal, Vivek K.; Wong, Franco N. C.; Shapiro, Jeffrey H.

    2016-01-01

    Reconstructing a scene's 3D structure and reflectivity accurately with an active imaging system operating in low-light-level conditions has wide-ranging applications, spanning biological imaging to remote sensing. Here we propose and experimentally demonstrate a depth and reflectivity imaging system with a single-photon camera that generates high-quality images from ∼1 detected signal photon per pixel. Previous achievements of similar photon efficiency have been with conventional raster-scanning data collection using single-pixel photon counters capable of ∼10-ps time tagging. In contrast, our camera's detector array requires highly parallelized time-to-digital conversions with photon time-tagging accuracy limited to ∼ns. Thus, we develop an array-specific algorithm that converts coarsely time-binned photon detections to highly accurate scene depth and reflectivity by exploiting both the transverse smoothness and longitudinal sparsity of natural scenes. By overcoming the coarse time resolution of the array, our framework uniquely achieves high photon efficiency in a relatively short acquisition time. PMID:27338821

  4. Photon-efficient imaging with a single-photon camera.

    PubMed

    Shin, Dongeek; Xu, Feihu; Venkatraman, Dheera; Lussana, Rudi; Villa, Federica; Zappa, Franco; Goyal, Vivek K; Wong, Franco N C; Shapiro, Jeffrey H

    2016-01-01

    Reconstructing a scene's 3D structure and reflectivity accurately with an active imaging system operating in low-light-level conditions has wide-ranging applications, spanning biological imaging to remote sensing. Here we propose and experimentally demonstrate a depth and reflectivity imaging system with a single-photon camera that generates high-quality images from ∼1 detected signal photon per pixel. Previous achievements of similar photon efficiency have been with conventional raster-scanning data collection using single-pixel photon counters capable of ∼10-ps time tagging. In contrast, our camera's detector array requires highly parallelized time-to-digital conversions with photon time-tagging accuracy limited to ∼ns. Thus, we develop an array-specific algorithm that converts coarsely time-binned photon detections to highly accurate scene depth and reflectivity by exploiting both the transverse smoothness and longitudinal sparsity of natural scenes. By overcoming the coarse time resolution of the array, our framework uniquely achieves high photon efficiency in a relatively short acquisition time. PMID:27338821

  5. Computational Modeling of Photonic Crystal Microcavity Single-Photon Emitters

    NASA Astrophysics Data System (ADS)

    Saulnier, Nicole A.

    Conventional cryptography is based on algorithms that are mathematically complex and difficult to solve, such as factoring large numbers. The advent of a quantum computer would render these schemes useless. As scientists work to develop a quantum computer, cryptographers are developing new schemes for unconditionally secure cryptography. Quantum key distribution has emerged as one of the potential replacements of classical cryptography. It relics on the fact that measurement of a quantum bit changes the state of the bit and undetected eavesdropping is impossible. Single polarized photons can be used as the quantum bits, such that a quantum system would in some ways mirror the classical communication scheme. The quantum key distribution system would include components that create, transmit and detect single polarized photons. The focus of this work is on the development of an efficient single-photon source. This source is comprised of a single quantum dot inside of a photonic crystal microcavity. To better understand the physics behind the device, a computational model is developed. The model uses Finite-Difference Time-Domain methods to analyze the electromagnetic field distribution in photonic crystal microcavities. It uses an 8-band k · p perturbation theory to compute the energy band structure of the epitaxially grown quantum dots. We discuss a method that combines the results of these two calculations for determining the spontaneous emission lifetime of a quantum dot in bulk material or in a microcavity. The computational models developed in this thesis are used to identify and characterize microcavities for potential use in a single-photon source. The computational tools developed are also used to investigate novel photonic crystal microcavities that incorporate 1D distributed Bragg reflectors for vertical confinement. It is found that the spontaneous emission enhancement in the quasi-3D cavities can be significantly greater than in traditional suspended slab

  6. Single-Atom Single-Photon Quantum Interface

    NASA Astrophysics Data System (ADS)

    Moehring, David; Bochmann, Joerg; Muecke, Martin; Specht, Holger; Weber, Bernhard; Wilk, Tatjana; Rempe, Gerhard

    2008-05-01

    By combining atom trapping techniques and cavity cooling schemes we are able to trap a single neutral atom inside a high-finesse cavity for several tens of seconds. We show that our coupled atom-cavity system can be used to generate single photons in a controlled way. With our long trapping times and high single-photon production efficiency, the non-classical properties of the emitted light can be shown in the photon correlations of a single atom. In a similar atom-cavity setup, we investigate the interface between atoms and photons by entangling a single atom with a single photon emitted into the cavity and by further mapping the quantum state of the atom onto a second single photon. These schemes are intrinsically deterministic and establish the basic element required to realize a distributed quantum network with individual atoms at rest as quantum memories and single flying photons as quantum messengers. This work was supported by the Deutsche Forschungsgemeinschaft, and the European Union SCALA and CONQUEST programs. D. L. M. acknowledges support from the Alexander von Humboldt Foundation.

  7. Single Photon Emission Computed Tomography (SPECT)

    MedlinePlus

    ... High Blood Pressure Tools & Resources Stroke More Single Photon Emission Computed Tomography (SPECT) Updated:Sep 11,2015 ... Persantine) or dobutamine. The tests may take between 2 and 2 1/2 hours. What happens after ...

  8. How a Single Photon Can Act as Many Photons

    NASA Astrophysics Data System (ADS)

    Dmochowski, Greg; Hallaji, Matin; Feizpour, Amir; Sinclair, Josiah; Steinberg, Aephraim

    2015-05-01

    We experimentally show how a single, post-selected photon may induce a non-linear cross-phase shift that is five times larger than the nominal single photon effect. Using a weak cross-Kerr interaction, we deterministically couple two coherent state optical fields and exploit weak-value amplification (WVA) to increase the effect that one field (the ``signal'') has on the other (the ``probe''). Due to the (weak) entangling interaction, appropriate preparation and post-selection of the signal field leads to interference of different possible probe states and an anomalously large cross-phase shift. This amplification only occurs for particular pre- and post-selections of the signal field; larger amplification arises when the final state is nearly orthogonal to the initially prepared state and, therefore, occurs less frequently. A laser-cooled cloud of 85Rb atoms is used to mediate the cross-Kerr interaction; the signal field imprints a phase shift on the probe laser, which grows linearly with the photon number in the signal pulse. That is, the probe effectively measures the photon number in the signal beam. The signal field is prepared in a given superposition of two polarizations, one of which interacts with the probe field more strongly than the other. After the interaction, detection of an individual signal photon (using a single photon detector) which is nearly orthogonally polarized causes the probe to acquire an additional single-photon phase shift that is amplified by the degree of orthogonality. We demonstrate an amplification factor of five.

  9. Bright Single Photon Emitter in Silicon Carbide

    NASA Astrophysics Data System (ADS)

    Lienhard, Benjamin; Schroeder, Tim; Mouradian, Sara; Dolde, Florian; Trong Tran, Toan; Aharonovich, Igor; Englund, Dirk

    Efficient, on-demand, and robust single photon emitters are of central importance to many areas of quantum information processing. Over the past 10 years, color centers in solids have emerged as excellent single photon emitters. Color centers in diamond are among the most intensively studied single photon emitters, but recently silicon carbide (SiC) has also been demonstrated to be an excellent host material. In contrast to diamond, SiC is a technologically important material that is widely used in optoelectronics, high power electronics, and microelectromechanical systems. It is commercially available in sizes up to 6 inches and processes for device engineering are well developed. We report on a visible-spectrum single photon emitter in 4H-SiC. The emitter is photostable at both room and low temperatures, and it enables 2 million photons/second from unpatterned bulk SiC. We observe two classes of orthogonally polarized emitters, each of which has parallel absorption and emission dipole orientations. Low temperature measurements reveal a narrow zero phonon line with linewidth < 0.1 nm that accounts for more than 30% of the total photoluminescence spectrum. To our knowledge, this SiC color emitter is the brightest stable room-temperature single photon emitter ever observed.

  10. Simple microcavity for single-photon generation.

    PubMed

    Plakhotnik, Taras

    2005-04-18

    A new design of an optical resonator for generation of single-photon pulses is proposed. The resonator is made of a cylindrical or spherical piece of a polymer squeezed between two flat dielectric mirrors. The mode characteristics of this resonator are calculated numerically. The numerical analysis is backed by a physical explanation. The decay time and the mode volume of the fundamental mode are sufficient for achieving more than 96% probability of generating a single-photon in a single-mode. The corresponding requirement for the reflectivity of the mirrors (~99.9%) and the losses in the polymer (100 dB/m) are quite modest. The resonator is suitable for single-photon generation based on optical pumping of a single quantum system such as an organic molecule, a diamond nanocrystal, or a semiconductor quantum dot if they are imbedded in the polymer. PMID:19495201

  11. Superconducting nanowire single photon detector on diamond

    SciTech Connect

    Atikian, Haig A.; Burek, Michael J.; Choy, Jennifer T.; Lončar, Marko; Eftekharian, Amin; Jafari Salim, A.; Hamed Majedi, A.

    2014-03-24

    Superconducting nanowire single photon detectors are fabricated directly on diamond substrates and their optical and electrical properties are characterized. Dark count performance and photon count rates are measured at varying temperatures for 1310 nm and 632 nm photons. A multi-step diamond surface polishing procedure is reported, involving iterative reactive ion etching and mechanical polishing to create a suitable diamond surface for the deposition and patterning of thin film superconducting layers. Using this approach, diamond substrates with less than 300 pm Root Mean Square surface roughness are obtained.

  12. Single photon avalanche diode radiation tests

    NASA Astrophysics Data System (ADS)

    Kodet, Jan; Prochazka, Ivan; Blazej, Josef; Sun, Xiaoli; Cavanaugh, John

    2012-12-01

    The single photon counting diodes are recently planned for applications in deep space missions. That is why the proton radiation and gamma ray radiation tests of silicon based single photon avalanche diodes were measured and compared. The main characteristic that changed after the irradiation was effective dark count rate, which was measured using actively quenching and gating circuit. The radiation reached 6.5 krad at 53 MeV protons energy and 34 krad using gamma ray radiation source 60Co. The annealing rates were monitored at room temperature and at 60 °C.

  13. Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium

    SciTech Connect

    Konrad, Thomas; Scherer, Artur; Nock, Michael; Audretsch, Juergen

    2006-03-15

    We propose a setup for a heralded, i.e., announced generation of a pure single-photon state given two imperfect sources whose outputs are represented by mixtures of the single-photon Fock state [1> with the vacuum [0>. Our purification scheme uses beam splitters, photodetection, and a two-photon-absorbing medium. The admixture of the vacuum is fully eliminated. We discuss two potential realizations of the scheme.

  14. Multidimensional time-correlated single photon counting

    NASA Astrophysics Data System (ADS)

    Becker, Wolfgang; Bergmann, Axel

    2006-10-01

    Time-correlated single photon counting (TCSPC) is based on the detection of single photons of a periodic light signal, measurement of the detection time of the photons, and the build-up of the photon distribution versus the time in the signal period. TCSPC achieves a near ideal counting efficiency and transit-time-spread-limited time resolution for a given detector. The drawback of traditional TCSPC is the low count rate, long acquisition time, and the fact that the technique is one-dimensional, i.e. limited to the recording of the pulse shape of light signals. We present an advanced TCSPC technique featuring multi-dimensional photon acquisition and a count rate close to the capability of currently available detectors. The technique is able to acquire photon distributions versus wavelength, spatial coordinates, and the time on the ps scale, and to record fast changes in the fluorescence lifetime and fluorescence intensity of a sample. Biomedical applications of advanced TCSPC techniques are time-domain optical tomography, recording of transient phenomena in biological systems, spectrally resolved fluorescence lifetime imaging, FRET experiments in living cells, and the investigation of dye-protein complexes by fluorescence correlation spectroscopy. We demonstrate the potential of the technique for selected applications.

  15. Transform-limited single photons from a single quantum dot

    PubMed Central

    Kuhlmann, Andreas V.; Prechtel, Jonathan H.; Houel, Julien; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D.; Warburton, Richard J.

    2015-01-01

    Developing a quantum photonics network requires a source of very-high-fidelity single photons. An outstanding challenge is to produce a transform-limited single-photon emitter to guarantee that single photons emitted far apart in the time domain are truly indistinguishable. This is particularly difficult in the solid-state as the complex environment is the source of noise over a wide bandwidth. A quantum dot is a robust, fast, bright and narrow-linewidth emitter of single photons; layer-by-layer growth and subsequent nano-fabrication allow the electronic and photonic states to be engineered. This represents a set of features not shared by any other emitter but transform-limited linewidths have been elusive. Here, we report transform-limited linewidths measured on second timescales, primarily on the neutral exciton but also on the charged exciton close to saturation. The key feature is control of the nuclear spins, which dominate the exciton dephasing via the Overhauser field. PMID:26348157

  16. Photonic multiqubit states from a single atom

    SciTech Connect

    Li Ying; Aolita, Leandro; Kwek, L. C.

    2011-03-15

    We propose a protocol for the creation of photonic Greenberger-Horne-Zeilinger and linear cluster states emitted from a single atom--or ion--coupled to an optical cavity field. The method is based on laser pulses with different polarizations and exploits the atomic transition amplitudes to state-selectively achieve the desired transitions. The scheme lies within reach of current technology.

  17. Interactive Screen Experiments with Single Photons

    ERIC Educational Resources Information Center

    Bronner, Patrick; Strunz, Andreas; Silberhorn, Christine; Meyn, Jan-Peter

    2009-01-01

    Single photons are used for fundamental quantum physics experiments as well as for applications. Originally being a topic of advance courses, such experiments are increasingly a subject of undergraduate courses. We provide interactive screen experiments (ISE) for supporting the work in a real laboratory, and for students who do not have access to…

  18. Deterministic Single-Phonon Source Triggered by a Single Photon

    NASA Astrophysics Data System (ADS)

    Söllner, Immo; Midolo, Leonardo; Lodahl, Peter

    2016-06-01

    We propose a scheme that enables the deterministic generation of single phonons at gigahertz frequencies triggered by single photons in the near infrared. This process is mediated by a quantum dot embedded on chip in an optomechanical circuit, which allows for the simultaneous control of the relevant photonic and phononic frequencies. We devise new optomechanical circuit elements that constitute the necessary building blocks for the proposed scheme and are readily implementable within the current state-of-the-art of nanofabrication. This will open new avenues for implementing quantum functionalities based on phonons as an on-chip quantum bus.

  19. Deterministic Single-Phonon Source Triggered by a Single Photon.

    PubMed

    Söllner, Immo; Midolo, Leonardo; Lodahl, Peter

    2016-06-10

    We propose a scheme that enables the deterministic generation of single phonons at gigahertz frequencies triggered by single photons in the near infrared. This process is mediated by a quantum dot embedded on chip in an optomechanical circuit, which allows for the simultaneous control of the relevant photonic and phononic frequencies. We devise new optomechanical circuit elements that constitute the necessary building blocks for the proposed scheme and are readily implementable within the current state-of-the-art of nanofabrication. This will open new avenues for implementing quantum functionalities based on phonons as an on-chip quantum bus. PMID:27341236

  20. Angle sensitive single photon avalanche diode

    SciTech Connect

    Lee, Changhyuk Johnson, Ben Molnar, Alyosha

    2015-06-08

    An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

  1. T-shaped single-photon router.

    PubMed

    Lu, Jing; Wang, Z H; Zhou, Lan

    2015-09-01

    We study the transport properties of a single photon scattered by a two-level system (TLS) in a T-shaped waveguide, which is made of two coupled-resonator waveguides (CRWs)- an infinite CRW and a semi-infinite CRW. The spontaneous emission of the TLS directs single photons from one CRW to the other. Although the transfer rate is different for the wave incident from different CRWs, due to the boundary breaking the translational symmetry, the boundary can enhance the transfer rate found in Phys. Rev. Lett. 111, 103604 (2013) and Phys. Rev. A 89, 013805 (2014), as the transfer rate could be unity for the wave incident from the semi-infinite CRW. PMID:26368401

  2. Multiple beam splitter for single photons

    SciTech Connect

    Wang Tun; Kostrun, Marijan; Yelin, S.F.

    2004-11-01

    We propose a method using 'light storage' and fractional stimulated Raman adiabatic passage (F-STIRAP) to get entangled multiple Fock states from a single photon. A light storage technique is used to store the quantum information of a single-photon pulse in atoms. F-STIRAP pulses then split the stored coherence, such that reading pulses retrieve the quantum information from this new coherence. Since each reading pulse only retrieves part of the total coherence, we can obtain entangled multiple Fock states with arbitrary relative amplitude. This method to create entanglement is versatile for obtaining frequency, time, and/or spatial entanglement. Indeed, we obtain a multiple beam splitter with easily adjustable parameters.

  3. Advantages of gated silicon single photon detectors

    NASA Astrophysics Data System (ADS)

    Legré, Matthieu; Lunghi, Tommaso; Stucki, Damien; Zbinden, Hugo

    2013-05-01

    We present gated silicon single photon detectors based on two commercially available avalanche photodiodes (APDs) and one customised APD from ID Quantique SA. This customised APD is used in a commercially available device called id110. A brief comparison of the two commercial APDs is presented. Then, the charge persistence effect of all of those detectors that occurs just after a strong illumination is shown and discussed.

  4. Characterization of photon statistics in a single-photon source via variable attenuation

    NASA Astrophysics Data System (ADS)

    Zhang, Shengli; Zou, Xubo; Li, Chuanfeng; Jin, Chenhui; Guo, Guangcan

    2009-10-01

    We propose a simple but effective scheme for characterizing photon-number statistics of a practical single-photon source. In this scheme, the variable attenuation method which frequently appears in decoy state quantum cryptography is utilized here to enhance the estimation of photon-number statistics. A much stricter bound for vacuum and single-photon proportions is obtained and this result, in turn, is shown to be applicable to the unconditional secure quantum cryptographic communication with single-photon devices.

  5. Characterization of photon statistics in a single-photon source via variable attenuation

    SciTech Connect

    Zhang Shengli; Zou Xubo; Li Chuanfeng; Guo Guangcan; Jin Chenhui

    2009-10-15

    We propose a simple but effective scheme for characterizing photon-number statistics of a practical single-photon source. In this scheme, the variable attenuation method which frequently appears in decoy state quantum cryptography is utilized here to enhance the estimation of photon-number statistics. A much stricter bound for vacuum and single-photon proportions is obtained and this result, in turn, is shown to be applicable to the unconditional secure quantum cryptographic communication with single-photon devices.

  6. Noiseless Conditional Teleportation of a Single Photon.

    PubMed

    Fuwa, Maria; Toba, Shunsuke; Takeda, Shuntaro; Marek, Petr; Mišta, Ladislav; Filip, Radim; van Loock, Peter; Yoshikawa, Jun-Ichi; Furusawa, Akira

    2014-11-28

    We experimentally demonstrate the noiseless teleportation of a single photon by conditioning on quadrature Bell measurement results near the origin in phase space and thereby circumventing the photon loss that otherwise occurs even in optimal gain-tuned continuous-variable quantum teleportation. In general, thanks to this loss suppression, the noiseless conditional teleportation can preserve the negativity of the Wigner function for an arbitrary pure input state and an arbitrary pure entangled resource state. In our experiment, the positive value of the Wigner function at the origin for the unconditional output state, W(0,0)=0.015±0.001, becomes clearly negative after conditioning, W(0,0)=-0.025±0.005, illustrating the advantage of noiseless conditional teleportation. PMID:25494071

  7. Purification of a single-photon nonlinearity.

    PubMed

    Snijders, H; Frey, J A; Norman, J; Bakker, M P; Langman, E C; Gossard, A; Bowers, J E; van Exter, M P; Bouwmeester, D; Löffler, W

    2016-01-01

    Single photon nonlinearities based on a semiconductor quantum dot in an optical microcavity are a promising candidate for integrated optical quantum information processing nodes. In practice, however, the finite quantum dot lifetime and cavity-quantum dot coupling lead to reduced fidelity. Here we show that, with a nearly polarization degenerate microcavity in the weak coupling regime, polarization pre- and postselection can be used to restore high fidelity. The two orthogonally polarized transmission amplitudes interfere at the output polarizer; for special polarization angles, which depend only on the device cooperativity, this enables cancellation of light that did not interact with the quantum dot. With this, we can transform incident coherent light into a stream of strongly correlated photons with a second-order correlation value up to 40, larger than previous experimental results, even in the strong-coupling regime. This purification technique might also be useful to improve the fidelity of quantum dot based logic gates. PMID:27573361

  8. Heralded single photon sources: a route towards quantum communication technology and photon standards

    NASA Astrophysics Data System (ADS)

    Castelletto, S. A.; Scholten, R. E.

    2008-03-01

    Single photon counting, based on single photon sources and detectors, is a key ingredient for certain applications aiming at new quantum information technologies. Quantum cryptography, quantum radiometry, distributed quantum computing, as well as adjacent technologies such as biomedical and astronomical imaging, and low power classical communication also rely on single-photon technology. This paper reviews the present status of single photon sources and related counting measurement techniques, based on correlated (or heralded) photons in parametric down-conversion, and their possible impact on the above mentioned technologies, as well as an assessment for photon standards in the future.

  9. Ultrafast electrical control of a resonantly driven single photon source

    SciTech Connect

    Cao, Y.; Bennett, A. J. Ellis, D. J. P.; Shields, A. J.; Farrer, I.; Ritchie, D. A.

    2014-08-04

    We demonstrate generation of a pulsed stream of electrically triggered single photons in resonance fluorescence, by applying high frequency electrical pulses to a single quantum dot in a p-i-n diode under resonant laser excitation. Single photon emission was verified, with the probability of multiple photon emission reduced to 2.8%. We show that despite the presence of charge noise in the emission spectrum of the dot, resonant excitation acts as a “filter” to generate narrow bandwidth photons.

  10. Quantum Overloading Cryptography Using Single-Photon Nonlocality

    NASA Astrophysics Data System (ADS)

    Tan, Yong-Gang; Cai, Qing-Yu; Shi, Ting-Yun

    2007-08-01

    Using the single-photon nonlocality, we propose a quantum novel overloading cryptography scheme, in which a single photon carries two bits information in one-way quantum channel. Two commutative modes of the single photon, the polarization mode and the spatial mode, are used to encode secret information. Strict time windows are set to detect the impersonation attack. The spatial mode which denotes the existence of photons is noncommutative with the phase of the photon, so that our scheme is secure against photon-number-splitting attack. Our protocol may be secure against individual attack.

  11. Extraction of a single photon from an optical pulse

    NASA Astrophysics Data System (ADS)

    Rosenblum, Serge; Bechler, Orel; Shomroni, Itay; Lovsky, Yulia; Guendelman, Gabriel; Dayan, Barak

    2016-01-01

    Removing a single photon from a pulse is one of the most elementary operations that can be performed on light, having both fundamental significance and practical applications in quantum communication and computation. So far, photon subtraction, in which the removed photon is detected and therefore irreversibly lost, has been implemented in a probabilistic manner with inherently low success rates using low-reflectivity beam splitters. Here we demonstrate a scheme for the deterministic extraction of a single photon from an incoming pulse. The removed photon is diverted to a different mode, enabling its use for other purposes, such as a photon number-splitting attack on quantum key distribution protocols. Our implementation makes use of single-photon Raman interaction (SPRINT) with a single atom near a nanofibre-coupled microresonator. The single-photon extraction probability in our current realization is limited mostly by linear loss, yet probabilities close to unity should be attainable with realistic experimental parameters.

  12. Dead Time of Single Photon Avalanche Diodes

    NASA Astrophysics Data System (ADS)

    Neri, L.; Tudisco, S.; Musumeci, F.; Scordino, A.; Fallica, G.; Mazzillo, M.; Zimbone, M.

    2011-06-01

    Single Photon Avalanche Diode (SPAD) is the new generation of Geiger-Muller counter device developed in semiconductor technology [S. Privitera et al. Sensors Journal, vol 8 Iss. 8 (2008) 4636; S. Tudisco et al. IEEE Sensors Journal vol 8 ISS 7-8 (2008) 1324; S. Cova et al. Applied Optics 35 (1996) 1956]. Physical dead time model and noise production process has been analyzed and their corrections have been performed [S.H. Lee, R.P. Gardner, M. Jae, Nucl. Instr. and Meth. in Phys. Res. B 263 (2007) 46]. We have been able to extract the real amount of incident photon rate up to 10 7cps using a device with 0.97μs total deadtime. We also developed the equation of the noise count rate vs incoming photon rate, supported by Montecarlo simulation and experimental data. We marked the difference between dark rate and noise count rate, and introduced the noise rate inside the hybrid deadtime equation used for SPAD device.

  13. Efficient single-photon entanglement concentration for quantum communications

    NASA Astrophysics Data System (ADS)

    Zhou, Lan; Sheng, Yu-Bo

    2014-02-01

    We present two entanglement concentration protocols for single-photon entanglement. The first protocol is implemented with linear optics. With the help of the 50:50 beam splitter, variable beam splitter and an auxiliary photon, a less-entangled single-photon state can be concentrated into a maximally single-photon entangled state with some probability. The second protocol is implemented with the cross-Kerr nonlinearity. With the help of the cross-Kerr nonlinearity, the sophisticated single photon detector is not required. Moreover, the second protocol can be reused to get higher success probability. All these advantages may make the protocols useful in the long-distance quantum communication.

  14. Integrated spatial multiplexing of heralded single-photon sources

    PubMed Central

    Collins, M.J.; Xiong, C.; Rey, I.H.; Vo, T.D.; He, J.; Shahnia, S.; Reardon, C.; Krauss, T.F.; Steel, M.J.; Clark, A.S.; Eggleton, B.J.

    2013-01-01

    The non-deterministic nature of photon sources is a key limitation for single-photon quantum processors. Spatial multiplexing overcomes this by enhancing the heralded single-photon yield without enhancing the output noise. Here the intrinsic statistical limit of an individual source is surpassed by spatially multiplexing two monolithic silicon-based correlated photon pair sources in the telecommunications band, demonstrating a 62.4% increase in the heralded single-photon output without an increase in unwanted multipair generation. We further demonstrate the scalability of this scheme by multiplexing photons generated in two waveguides pumped via an integrated coupler with a 63.1% increase in the heralded photon rate. This demonstration paves the way for a scalable architecture for multiplexing many photon sources in a compact integrated platform and achieving efficient two-photon interference, required at the core of optical quantum computing and quantum communication protocols. PMID:24107840

  15. Recent advances in superconducting nanowire single photon detectors for single-photon imaging

    NASA Astrophysics Data System (ADS)

    Verma, V. B.; Allman, M. S.; Stevens, M.; Gerrits, T.; Horansky, R. D.; Lita, A. E.; Marsili, F.; Beyer, A.; Shaw, M. D.; Stern, J. A.; Mirin, R. P.; Nam, S. W.

    2016-05-01

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array, as well as characterization measurements are discussed.

  16. Quantum Logic with Cavity Photons From Single Atoms.

    PubMed

    Holleczek, Annemarie; Barter, Oliver; Rubenok, Allison; Dilley, Jerome; Nisbet-Jones, Peter B R; Langfahl-Klabes, Gunnar; Marshall, Graham D; Sparrow, Chris; O'Brien, Jeremy L; Poulios, Konstantinos; Kuhn, Axel; Matthews, Jonathan C F

    2016-07-01

    We demonstrate quantum logic using narrow linewidth photons that are produced with an a priori nonprobabilistic scheme from a single ^{87}Rb atom strongly coupled to a high-finesse cavity. We use a controlled-not gate integrated into a photonic chip to entangle these photons, and we observe nonclassical correlations between photon detection events separated by periods exceeding the travel time across the chip by 3 orders of magnitude. This enables quantum technology that will use the properties of both narrow-band single photon sources and integrated quantum photonics. PMID:27447506

  17. Quantum Logic with Cavity Photons From Single Atoms

    NASA Astrophysics Data System (ADS)

    Holleczek, Annemarie; Barter, Oliver; Rubenok, Allison; Dilley, Jerome; Nisbet-Jones, Peter B. R.; Langfahl-Klabes, Gunnar; Marshall, Graham D.; Sparrow, Chris; O'Brien, Jeremy L.; Poulios, Konstantinos; Kuhn, Axel; Matthews, Jonathan C. F.

    2016-07-01

    We demonstrate quantum logic using narrow linewidth photons that are produced with an a priori nonprobabilistic scheme from a single 87Rb atom strongly coupled to a high-finesse cavity. We use a controlled-not gate integrated into a photonic chip to entangle these photons, and we observe nonclassical correlations between photon detection events separated by periods exceeding the travel time across the chip by 3 orders of magnitude. This enables quantum technology that will use the properties of both narrow-band single photon sources and integrated quantum photonics.

  18. Generation of Fourier-transform-limited heralded single photons

    SciTech Connect

    U'Ren, Alfred B.; Jeronimo-Moreno, Yasser; Garcia-Gracia, Hipolito

    2007-02-15

    In this paper we study the spectral (temporal) properties of heralded single photon wave packets, triggered by the detection of an idler photon in the process of parametric down conversion. The generated single photons are studied within the framework of the chronocyclic Wigner function, from which the single photon spectral width and temporal duration can be computed. We derive specific conditions on the two-photon joint spectral amplitude which result in both pure and Fourier-transform-limited heralded single photons. Likewise, we present specific source geometries which lead to the fulfillment of these conditions and show that one of these geometries leads, for a given pump bandwidth, to the temporally shortest possible heralded single photon wave packets.

  19. Graphene Josephson Junction Single Photon Detector

    NASA Astrophysics Data System (ADS)

    Walsh, Evan D.; Lee, Gil-Ho; Efetov, Dmitri K.; Heuck, Mikkel; Crossno, Jesse; Taniguchi, Takashi; Watanabe, Kenji; Ohki, Thomas A.; Kim, Philip; Englund, Dirk; Fong, Kin Chung

    Single photon detectors (SPDs) have found use across a wide array of applications depending on the wavelength to which they are sensitive. Graphene, because of its linear, gapless dispersion near the Dirac point, has a flat, wide bandwidth absorption that can be enhanced to near 100 % through the use of resonant structures making it a promising candidate for broadband SPDs. Upon absorbing a photon in the optical to mid-infrared range, a small (~10 μm2) sheet of graphene at cryogenic temperatures can experience a significant increase in electronic temperature due to its extremely low heat capacity. At 1550 nm, for example, calculations show that the temperature could rise by as much as 500 %. This temperature increase could be detected with near perfect quantum efficiency by making the graphene the weak link in a Josephson junction (JJ). We present a theoretical model demonstrating that such a graphene JJ SPD could operate at the readily achievable temperature of 3 K with near zero dark count, sub-50 ps timing jitter, and sub-5 ns dead time and report on the progress toward experimentally realizing the device.

  20. Single-photon emitting diode in silicon carbide.

    PubMed

    Lohrmann, A; Iwamoto, N; Bodrog, Z; Castelletto, S; Ohshima, T; Karle, T J; Gali, A; Prawer, S; McCallum, J C; Johnson, B C

    2015-01-01

    Electrically driven single-photon emitting devices have immediate applications in quantum cryptography, quantum computation and single-photon metrology. Mature device fabrication protocols and the recent observations of single defect systems with quantum functionalities make silicon carbide an ideal material to build such devices. Here, we demonstrate the fabrication of bright single-photon emitting diodes. The electrically driven emitters display fully polarized output, superior photon statistics (with a count rate of >300 kHz) and stability in both continuous and pulsed modes, all at room temperature. The atomic origin of the single-photon source is proposed. These results provide a foundation for the large scale integration of single-photon sources into a broad range of applications, such as quantum cryptography or linear optics quantum computing. PMID:26205309

  1. Circuit electromechanics with single photon strong coupling

    SciTech Connect

    Xue, Zheng-Yuan Yang, Li-Na; Zhou, Jian

    2015-07-13

    In circuit electromechanics, the coupling strength is usually very small. Here, replacing the capacitor in circuit electromechanics by a superconducting flux qubit, we show that the coupling among the qubit and the two resonators can induce effective electromechanical coupling which can attain the strong coupling regime at the single photon level with feasible experimental parameters. We use dispersive couplings among two resonators and the qubit while the qubit is also driven by an external classical field. These couplings form a three-wave mixing configuration among the three elements where the qubit degree of freedom can be adiabatically eliminated, and thus results in the enhanced coupling between the two resonators. Therefore, our work constitutes the first step towards studying quantum nonlinear effect in circuit electromechanics.

  2. Experimental generation of single photons via active multiplexing

    SciTech Connect

    Ma Xiaosong; Zotter, Stefan; Kofler, Johannes; Jennewein, Thomas; Zeilinger, Anton

    2011-04-15

    An on-demand single-photon source is a fundamental building block in quantum science and technology. We experimentally demonstrate the proof of concept for a scheme to generate on-demand single photons via actively multiplexing several heralded photons probabilistically produced from pulsed spontaneous parametric down-conversions (SPDCs). By utilizing a four-photon-pair source, an active feed-forward technique, and an ultrafast single-photon router, we show a fourfold enhancement of the output photon rate. Simultaneously, we maintain the quality of the output single-photon states, confirmed by correlation measurements. We also experimentally verify, via Hong-Ou-Mandel interference, that the router does not affect the indistinguishability of the single photons. Furthermore, we give numerical simulations, which indicate that photons based on multiplexing of four SPDC sources can outperform the heralding based on highly advanced photon-number-resolving detectors. Our results show a route for on-demand single-photon generation and the practical realization of scalable linear optical quantum-information processing.

  3. Single-photon detection using magnesium diboride superconducting nanowires

    NASA Astrophysics Data System (ADS)

    Shibata, H.; Takesue, H.; Honjo, T.; Akazaki, T.; Tokura, Y.

    2010-11-01

    We fabricated 10 nm thick MgB2 nanowires with a width down to 100 nm using the liftoff process. The I-V characteristics of the nanowire show hysteresis and a sharp voltage jump at Ic. Though a 150 nm wide nanowire exhibits the capacity for detecting a single photon at 405 nm wavelength, the nanowire is too wide to detect a single photon at 1560 nm. A 100 nm wide nanowire exhibits the capacity for detecting single photons in the 405-1560 nm wavelength range. This indicates a possible application of MgB2 as a high-performance superconducting nanowire single-photon detector.

  4. Waveguide-Coupled Superconducting Nanowire Single-Photon Detectors

    NASA Technical Reports Server (NTRS)

    Beyer, Andrew D.; Briggs, Ryan M.; Marsili, Francesco; Cohen, Justin D.; Meenehan, Sean M.; Painter, Oskar J.; Shaw, Matthew D.

    2015-01-01

    We have demonstrated WSi-based superconducting nanowire single-photon detectors coupled to SiNx waveguides with integrated ring resonators. This photonics platform enables the implementation of robust and efficient photon-counting detectors with fine spectral resolution near 1550 nm.

  5. Experimental position-time entanglement with degenerate single photons

    SciTech Connect

    Bennett, A. J.; Gevaux, D. G.; Yuan, Z. L.; Shields, A. J.; Atkinson, P.; Ritchie, D. A.

    2008-02-15

    We report an experiment in which two-photon interference occurs between degenerate single photons that never meet. The two photons travel in opposite directions through our fiber-optic interferometer and interference occurs when the photons reach two different, spatially separated, two-by-two couplers at the same time. We show that this experiment is analogous to the conventional Franson-type entanglement experiment where the photons are entangled in position and time. We measure wave-function overlaps for the two photons as high as 94{+-}3%.

  6. Two-photon-induced singlet fission in rubrene single crystal

    NASA Astrophysics Data System (ADS)

    Ma, Lin; Galstyan, Gegham; Zhang, Keke; Kloc, Christian; Sun, Handong; Soci, Cesare; Michel-Beyerle, Maria E.; Gurzadyan, Gagik G.

    2013-05-01

    The two-photon-induced singlet fission was observed in rubrene single crystal and studied by use of femtosecond pump-probe spectroscopy. The location of two-photon excited states was obtained from the nondegenerate two-photon absorption (TPA) spectrum. Time evolution of the two-photon-induced transient absorption spectra reveals the direct singlet fission from the two-photon excited states. The TPA absorption coefficient of rubrene single crystal is 52 cm/GW at 740 nm, as obtained from Z-scan measurements. Quantum chemical calculations based on time-dependent density functional theory support our experimental data.

  7. Quantum Probability Cancellation Due to a Single-Photon State

    NASA Technical Reports Server (NTRS)

    Ou, Z. Y.

    1996-01-01

    When an N-photon state enters a lossless symmetric beamsplitter from one input port, the photon distribution for the two output ports has the form of Bernouli Binormial, with highest probability at equal partition (N/2 at one outport and N/2 at the other). However, injection of a single photon state at the other input port can dramatically change the photon distribution at the outputs, resulting in zero probability at equal partition. Such a strong deviation from classical particle theory stems from quantum probability amplitude cancellation. The effect persists even if the N-photon state is replaced by an arbitrary state of light. A special case is the coherent state which corresponds to homodyne detection of a single photon state and can lead to the measurement of the wave function of a single photon state.

  8. Interferometric Quantum-Nondemolition Single-Photon Detectors

    NASA Technical Reports Server (NTRS)

    Kok, Peter; Lee, Hwang; Dowling, Jonathan

    2007-01-01

    Two interferometric quantum-nondemolition (QND) devices have been proposed: (1) a polarization-independent device and (2) a polarization-preserving device. The prolarization-independent device works on an input state of up to two photons, whereas the polarization-preserving device works on a superposition of vacuum and single- photon states. The overall function of the device would be to probabilistically generate a unique detector output only when its input electromagnetic mode was populated by a single photon, in which case its output mode would also be populated by a single photon. Like other QND devices, the proposed devices are potentially useful for a variety of applications, including such areas of NASA interest as quantum computing, quantum communication, detection of gravity waves, as well as pedagogical demonstrations of the quantum nature of light. Many protocols in quantum computation and quantum communication require the possibility of detecting a photon without destroying it. The only prior single- photon-detecting QND device is based on quantum electrodynamics in a resonant cavity and, as such, it depends on the photon frequency. Moreover, the prior device can distinguish only between one photon and no photon. The proposed interferometric QND devices would not depend on frequency and could distinguish between (a) one photon and (b) zero or two photons. The first proposed device is depicted schematically in Figure 1. The input electromagnetic mode would be a superposition of a zero-, a one-, and a two-photon quantum state. The overall function of the device would be to probabilistically generate a unique detector output only when its input electromagnetic mode was populated by a single photon, in which case its output mode also would be populated by a single photon.

  9. Electrically driven single photon source at high temperature.

    PubMed

    El Halawany, Ahmed; Leuenberger, Michael N

    2016-03-01

    We present a theoretical model for an electrically driven single photon source operating at high temperatures. We show that decoherence, which is usually the main obstacle for operating single photon sources at high temperatures, ensures an efficient operation of the presented electrically driven single photon source at high temperatures. The single-photon source is driven by a single electron source attached to a heterostructure semiconductor nanoring. The electron's dynamics in the nanoring and the subsequent recombination with the hole is described by the generalized master equation with a Hamiltonian based on tight-binding model, taking into account the electron-LO phonon interaction. As a result of decoherence, an almost 100% single photon emission with a strong antibunching behavior i.e. g(2)(0) < 1 at high temperature up to 300 K is achieved. PMID:26828830

  10. Electrically driven single photon source at high temperature

    NASA Astrophysics Data System (ADS)

    El Halawany, Ahmed; Leuenberger, Michael N.

    2016-03-01

    We present a theoretical model for an electrically driven single photon source operating at high temperatures. We show that decoherence, which is usually the main obstacle for operating single photon sources at high temperatures, ensures an efficient operation of the presented electrically driven single photon source at high temperatures. The single-photon source is driven by a single electron source attached to a heterostructure semiconductor nanoring. The electron’s dynamics in the nanoring and the subsequent recombination with the hole is described by the generalized master equation with a Hamiltonian based on tight-binding model, taking into account the electron-LO phonon interaction. As a result of decoherence, an almost 100% single photon emission with a strong antibunching behavior i.e. {{g}(2)}(0)\\ll 1 at high temperature up to 300 K is achieved.

  11. Direct fiber-coupled single photon source based on a photonic crystal waveguide

    SciTech Connect

    Ahn, Byeong-Hyeon Lee, Chang-Min; Lim, Hee-Jin; Schlereth, Thomas W.; Kamp, Martin; Höfling, Sven; Lee, Yong-Hee

    2015-08-24

    A single photon source plays a key role in quantum applications such as quantum computers and quantum communications. Epitaxially grown quantum dots are one of the promising platforms to implement a good single photon source. However, it is challenging to realize an efficient single photon source based on semiconductor materials due to their high refractive index. Here we demonstrate a direct fiber coupled single photon source with high collection efficiency by employing a photonic crystal (PhC) waveguide and a tapered micro-fiber. To confirm the single photon nature, the second-order correlation function g{sup (2)}(τ) is measured with a Hanbury Brown-Twiss setup. The measured g{sup (2)}(0) value is 0.15, and we can estimate 24% direct collection efficiency from a quantum dot to the fiber.

  12. Active temporal multiplexing of indistinguishable heralded single photons.

    PubMed

    Xiong, C; Zhang, X; Liu, Z; Collins, M J; Mahendra, A; Helt, L G; Steel, M J; Choi, D-Y; Chae, C J; Leong, P H W; Eggleton, B J

    2016-01-01

    It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong-Ou-Mandel quantum interference with a 91±16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies. PMID:26996317

  13. Active temporal multiplexing of indistinguishable heralded single photons

    NASA Astrophysics Data System (ADS)

    Xiong, C.; Zhang, X.; Liu, Z.; Collins, M. J.; Mahendra, A.; Helt, L. G.; Steel, M. J.; Choi, D.-Y.; Chae, C. J.; Leong, P. H. W.; Eggleton, B. J.

    2016-03-01

    It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong-Ou-Mandel quantum interference with a 91+/-16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies.

  14. Active temporal multiplexing of indistinguishable heralded single photons

    PubMed Central

    Xiong, C.; Zhang, X.; Liu, Z.; Collins, M. J.; Mahendra, A.; Helt, L. G.; Steel, M. J.; Choi, D. -Y.; Chae, C. J.; Leong, P. H. W.; Eggleton, B. J.

    2016-01-01

    It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong–Ou–Mandel quantum interference with a 91±16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies. PMID:26996317

  15. Direct detection of a single photon by humans.

    PubMed

    Tinsley, Jonathan N; Molodtsov, Maxim I; Prevedel, Robert; Wartmann, David; Espigulé-Pons, Jofre; Lauwers, Mattias; Vaziri, Alipasha

    2016-01-01

    Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds. PMID:27434854

  16. Direct detection of a single photon by humans

    PubMed Central

    Tinsley, Jonathan N.; Molodtsov, Maxim I.; Prevedel, Robert; Wartmann, David; Espigulé-Pons, Jofre; Lauwers, Mattias; Vaziri, Alipasha

    2016-01-01

    Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds. PMID:27434854

  17. Single photon emission from ZnO nanoparticles

    SciTech Connect

    Choi, Sumin; Ton-That, Cuong; Phillips, Matthew R.; Aharonovich, Igor; Johnson, Brett C.; Castelletto, Stefania

    2014-06-30

    Room temperature single photon emitters are very important resources for photonics and emerging quantum technologies. In this work, we study single photon emission from defect centers in 20 nm zinc oxide (ZnO) nanoparticles. The emitters exhibit bright broadband fluorescence in the red spectral range centered at 640 nm with polarized excitation and emission. The studied emitters showed continuous blinking; however, bleaching can be suppressed using a polymethyl methacrylate coating. Furthermore, hydrogen termination increased the density of single photon emitters. Our results will contribute to the identification of quantum systems in ZnO.

  18. New Generation of Superconducting Nanowire Single-Photon Detectors

    NASA Astrophysics Data System (ADS)

    Goltsman, G. N.

    2015-09-01

    We present an overview of recent results for new generation of infrared and optical superconducting nanowire single-photon detectors (SNSPDs) that has already demonstrated a performance that makes them devices-of-choice for many applications. SNSPDs provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, SNSPDs are also compatible with an integrated optical platform as a crucial requirement for applications in emerging quantum photonic technologies. By embedding SNSPDs in nanophotonic circuits we realize waveguide integrated single photon detectors which unite all desirable detector properties in a single device.

  19. Characterization of the nonclassical nature of conditionally prepared single photons

    SciTech Connect

    U'Ren, Alfred B.; Silberhorn, Christine; Ball, Jonathan L.; Banaszek, Konrad; Walmsley, Ian A.

    2005-08-15

    A reliable single photon source is a prerequisite for linear optical quantum computation and for secure quantum key distribution. A criterion yielding a conclusive test of the single photon character of a given source, attainable with realistic detectors, is therefore highly desirable. In the context of heralded single photon sources, such a criterion should be sensitive to the effects of higher photon number contributions, and to vacuum introduced through optical losses, which tend to degrade source performance. In this Rapid Communication we present, theoretically and experimentally, a criterion meeting the above requirements.

  20. Single pairs of time-bin-entangled photons

    NASA Astrophysics Data System (ADS)

    Versteegh, Marijn A. M.; Reimer, Michael E.; van den Berg, Aafke A.; Juska, Gediminas; Dimastrodonato, Valeria; Gocalinska, Agnieszka; Pelucchi, Emanuele; Zwiller, Val

    2015-09-01

    Time-bin-entangled photons are ideal for long-distance quantum communication via optical fibers. Here we present a source where, even at high creation rates, each excitation pulse generates, at most, one time-bin-entangled pair. This is important for the accuracy and security of quantum communication. Our site-controlled quantum dot generates single polarization-entangled photon pairs, which are then converted, without loss of entanglement strength, into single time-bin-entangled photon pairs.

  1. Single-Photon LIDAR for Vegetation Analysis

    NASA Astrophysics Data System (ADS)

    Rosette, J.; Field, C.; Nelson, R. F.; Decola, P.; Cook, B. D.; Degnan, J. J.

    2011-12-01

    Lidar is now an established and recognised technology which has been widely applied to assist forest inventory, monitoring and management. Small footprint lidar systems produce dense 'point clouds' from intercepted surfaces which, after classification of ground and vegetation returns, can be related to important forest biophysical parameters such as biomass or carbon. Within the context of NASA's Carbon Monitoring System (CMS) initiative (NASA, 2010), the prototype 100 beam, single-photon, scanning lidar, developed by Sigma Space Corporation, USA, is tested to assess the potential of this sensor for vegetation analysis. This emerging lidar technology is currently generally operated at green wavelengths (532 nm) and, like more conventional discrete return NIR lidar sensors, produces point clouds of intercepted surfaces. However, the high pulse repetition rate (20 kHz) and multibeam approach produces an unprecedented measurement rate (up to 2 Million pixels per second) and a correspondingly high point density. Furthermore, the single photon sensitivity enables the technique to be more easily extended to high altitudes and therefore larger swath widths. Additionally, CW diode laser pumping and a low laser pulse energy (6 μJ at 532 nm) favour an extended laser lifetime while the much lower energy per beamlet (~50nJ) ensures eye safety despite operating at a visible wavelength. Furthermore, the short laser pulse duration (0.7ns) allows the surface to be located with high vertical precision. Although the 532 nm green wavelength lies near the peak of the solar output, the spatial and temporal coherence of the surface returns, combined with stringent instrument specifications (small detector field of view and narrow optical band-pass filter), allow solid surfaces to be distinguished from the solar background during daylight operations. However, for extended volumetric scatterers such as tree canopies, some amount of solar noise is likely to be mixed in with valid biomass

  2. Single-molecule localization software applied to photon counting imaging.

    PubMed

    Hirvonen, Liisa M; Kilfeather, Tiffany; Suhling, Klaus

    2015-06-01

    Centroiding in photon counting imaging has traditionally been accomplished by a single-step, noniterative algorithm, often implemented in hardware. Single-molecule localization techniques in superresolution fluorescence microscopy are conceptually similar, but use more sophisticated iterative software-based fitting algorithms to localize the fluorophore. Here, we discuss common features and differences between single-molecule localization and photon counting imaging and investigate the suitability of single-molecule localization software for photon event localization. We find that single-molecule localization software packages designed for superresolution microscopy-QuickPALM, rapidSTORM, and ThunderSTORM-can work well when applied to photon counting imaging with a microchannel-plate-based intensified camera system: photon event recognition can be excellent, fixed pattern noise can be low, and the microchannel plate pores can easily be resolved. PMID:26192667

  3. Telecom-heralded single-photon absorption by a single atom

    NASA Astrophysics Data System (ADS)

    Lenhard, Andreas; Bock, Matthias; Becher, Christoph; Kucera, Stephan; Brito, José; Eich, Pascal; Müller, Philipp; Eschner, Jürgen

    2015-12-01

    We present, characterize, and apply the architecture of a photonic quantum interface between the near infrared and telecom spectral regions. A singly resonant optical parametric oscillator (OPO) operated below threshold, in combination with external filters, generates high-rate (>2.5 ×106s-1 ) narrowband photon pairs (˜7 MHz bandwidth); the signal photons are tuned to resonance with an atomic transition in Ca+, while the idler photons are at telecom wavelength. Interface operation is demonstrated through high-rate absorption of single photons by a single trapped ion (˜670 s-1 ), heralded by coincident telecom photons.

  4. Efficient Generation of Frequency-Multiplexed Entangled Single Photons

    NASA Astrophysics Data System (ADS)

    Qiu, Tian-Hui; Xie, Min

    2016-08-01

    We present two schemes to generate frequency-multiplexed entangled (FME) single photons by coherently mapping photonic entanglement into and out of a quantum memory based on Raman interactions. By splitting a single photon and performing subsequent state transfer, we separate the generation of entanglement and its frequency conversion, and find that the both progresses have the characteristic of inherent determinacy. Our theory can reproduce the prominent features of observed results including pulse shapes and the condition for deterministically generating the FME single photons. The schemes are suitable for the entangled photon pairs with a wider frequency range, and could be immune to the photon loss originating from cavity-mode damping, spontaneous emission, and the dephasing due to atomic thermal motion. The sources might have significant applications in wavelength-division-multiplexing quantum key distribution.

  5. Single photon laser altimeter data processing, analysis and experimental validation

    NASA Astrophysics Data System (ADS)

    Vacek, Michael; Peca, Marek; Michalek, Vojtech; Prochazka, Ivan

    2015-10-01

    Spaceborne laser altimeters are common instruments on-board the rendezvous spacecraft. This manuscript deals with the altimeters using a single photon approach, which belongs to the family of time-of-flight range measurements. Moreover, the single photon receiver part of the altimeter may be utilized as an Earth-to-spacecraft link enabling one-way ranging, time transfer and data transfer. The single photon altimeters evaluate actual altitude through the repetitive detections of single photons of the reflected laser pulses. We propose the single photon altimeter signal processing and data mining algorithm based on the Poisson statistic filter (histogram method) and the modified Kalman filter, providing all common altimetry products (altitude, slope, background photon flux and albedo). The Kalman filter is extended for the background noise filtering, the varying slope adaptation and the non-causal extension for an abrupt slope change. Moreover, the algorithm partially removes the major drawback of a single photon altitude reading, namely that the photon detection measurement statistics must be gathered. The developed algorithm deduces the actual altitude on the basis of a single photon detection; thus, being optimal in the sense that each detected signal photon carrying altitude information is tracked and no altitude information is lost. The algorithm was tested on the simulated datasets and partially cross-probed with the experimental data collected using the developed single photon altimeter breadboard based on the microchip laser with the pulse energy on the order of microjoule and the repetition rate of several kilohertz. We demonstrated that such an altimeter configuration may be utilized for landing or hovering a small body (asteroid, comet).

  6. Room-temperature single-photon sources based on nanocrystal fluorescence in photonic/plasmonic nanostructures

    NASA Astrophysics Data System (ADS)

    Lukishova, S. G.; Winkler, J. M.; Bissell, L. J.; Mihaylova, D.; Liapis, Andreas C.; Shi, Z.; Goldberg, D.; Menon, V. M.; Boyd, R. W.; Chen, G.; Prasad, P.

    2014-10-01

    Results are presented here towards robust room-temperature SPSs based on fluorescence in nanocrystals: colloidal quantum dots, color-center diamonds and doped with trivalent rare-earth ions (TR3+). We used cholesteric chiral photonic bandgap and Bragg-reflector microcavities for single emitter fluorescence enhancement. We also developed plasmonic bowtie nanoantennas and 2D-Si-photonic bandgap microcavities. The paper also provides short outlines of other technologies for room-temperature single-photon sources.

  7. A four-pixel single-photon pulse-position array fabricated from WSi superconducting nanowire single-photon detectors

    SciTech Connect

    Verma, V. B. Horansky, R.; Lita, A. E.; Mirin, R. P.; Nam, S. W.; Marsili, F.; Stern, J. A.; Shaw, M. D.

    2014-02-03

    We demonstrate a scalable readout scheme for an infrared single-photon pulse-position camera consisting of WSi superconducting nanowire single-photon detectors. For an N × N array, only 2 × N wires are required to obtain the position of a detection event. As a proof-of-principle, we show results from a 2 × 2 array.

  8. Responses of retinal rods to single photons.

    PubMed Central

    Baylor, D A; Lamb, T D; Yau, K W

    1979-01-01

    1. A suction electrode was used to record the membrane current of single rod outer segments in pieces of toad retina. During dim illumination the membrane current showed pronounced fluctuations. 2. Amplitude histograms of responses to dim flashes of fixed intensity exhibited two discrete peaks, one at 0 pA and one near 1 pA, suggesting that the response was quantized. By setting a criterion amplitude level, flash responses could be classed as 'failures' (no response) or as 'successes' (at least one quantal event). 3. The variation of fraction of successes with flash intensity was consistent with the hypothesis that each quantal electrical event resulted from a single photoisomerization. 4. The quantal event had a mean amplitude of about 1 pA (5% of the standing dark current) and a standard deviation of 0.2 pA. Dispersion in the event amplitude prevented identification of histogram peaks corresponding to two or more photoisomerizations. 5. Individual quantal responses exhibited a smooth shape very similar to that of the average quantal response. This suggests that a single photoisomerization releases many particles of transmitter and that radial diffusion of internal transmitter is not a major source of delay in the light response. 6. The 'quantum efficiency' with which an absorbed photon generated an electrical event was measured as 0.5 +/- 0.1 (S.E. of mean, n = 4). This is slightly lower than the quantum efficiency of photoisomerization obtained previously for rhodopsin in solution. 7. At wavelengths between 420 and 700 nm the quantal event was invariant in size, although the cell's sensitivity varied over a range of 10(5). 8. The power spectrum of the fluctuations in dim steady light was predicted by assuming that a random series of quantal events occurred independently. 9. In brighter light the fluctuations were faster, and the response to an incremental flash was reduced in size and duration. The power spectrum could be predicted by assuming random

  9. Quantum-dot-spin single-photon interface.

    PubMed

    Yilmaz, S T; Fallahi, P; Imamoğlu, A

    2010-07-16

    Using background-free detection of spin-state-dependent resonance fluorescence from a single-electron charged quantum dot with an efficiency of 0.1%, we realize a classical single spin-photon interface where the detection of a scattered photon with 300 ps time resolution projects the quantum dot spin to a definite spin eigenstate with fidelity exceeding 99%. The bunching of resonantly scattered photons reveals information about electron spin dynamics. High-fidelity fast spin-state initialization heralded by a single photon enables the realization of quantum information processing tasks such as nondeterministic distant spin entanglement. Given that we could suppress the measurement backaction to well below the natural spin-flip rate, realization of a quantum nondemolition measurement of a single spin could be achieved by increasing the fluorescence collection efficiency by a factor exceeding 10 using a photonic nanostructure. PMID:20867763

  10. Impossibility of faithfully storing single photons with the three-pulse photon echo

    SciTech Connect

    Sangouard, Nicolas; Minar, Jiri; Afzelius, Mikael; Gisin, Nicolas; Riedmatten, Hugues de; Simon, Christoph; Tittel, Wolfgang; Chaneliere, Thierry; Le Goueet, Jean-Louis

    2010-06-15

    The three-pulse photon echo is a well-known technique to store intense light pulses in an inhomogeneously broadened atomic ensemble. This protocol is attractive because it is relatively simple and it is well suited for the storage of multiple temporal modes. Furthermore, it offers very long storage times, greater than the phase relaxation time. Here, we consider the three-pulse photon echo in both two- and three-level systems as a potential technique for the storage of light at the single-photon level. By explicit calculations, we show that the ratio between the echo signal corresponding to a single-photon input and the noise is smaller than one. This severely limits the achievable fidelity of the quantum state storage, making the three-pulse photon echo unsuitable for single-photon quantum memory.

  11. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection

    NASA Astrophysics Data System (ADS)

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-03-01

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn ``photon-switches'' to ``OFF'' state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished.

  12. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection

    PubMed Central

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-01-01

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn “photon-switches” to “OFF” state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished. PMID:25797442

  13. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection.

    PubMed

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-01-01

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn "photon-switches" to "OFF" state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished. PMID:25797442

  14. A photon-photon quantum gate based on a single atom in an optical resonator.

    PubMed

    Hacker, Bastian; Welte, Stephan; Rempe, Gerhard; Ritter, Stephan

    2016-08-11

    That two photons pass each other undisturbed in free space is ideal for the faithful transmission of information, but prohibits an interaction between the photons. Such an interaction is, however, required for a plethora of applications in optical quantum information processing. The long-standing challenge here is to realize a deterministic photon-photon gate, that is, a mutually controlled logic operation on the quantum states of the photons. This requires an interaction so strong that each of the two photons can shift the other's phase by π radians. For polarization qubits, this amounts to the conditional flipping of one photon's polarization to an orthogonal state. So far, only probabilistic gates based on linear optics and photon detectors have been realized, because "no known or foreseen material has an optical nonlinearity strong enough to implement this conditional phase shift''. Meanwhile, tremendous progress in the development of quantum-nonlinear systems has opened up new possibilities for single-photon experiments. Platforms range from Rydberg blockade in atomic ensembles to single-atom cavity quantum electrodynamics. Applications such as single-photon switches and transistors, two-photon gateways, nondestructive photon detectors, photon routers and nonlinear phase shifters have been demonstrated, but none of them with the ideal information carriers: optical qubits in discriminable modes. Here we use the strong light-matter coupling provided by a single atom in a high-finesse optical resonator to realize the Duan-Kimble protocol of a universal controlled phase flip (π phase shift) photon-photon quantum gate. We achieve an average gate fidelity of (76.2 ± 3.6) per cent and specifically demonstrate the capability of conditional polarization flipping as well as entanglement generation between independent input photons. This photon-photon quantum gate is a universal quantum logic element, and therefore could perform most existing two-photon operations

  15. Achieving nonreciprocal unidirectional single-photon quantum transport using the photonic Aharonov-Bohm effect.

    PubMed

    Yuan, Luqi; Xu, Shanshan; Fan, Shanhui

    2015-11-15

    We show that nonreciprocal unidirectional single-photon quantum transport can be achieved with the photonic Aharonov-Bohm effect. The system consists of a 1D waveguide coupling to two three-level atoms of the V-type. The two atoms, in addition, are each driven by an external coherent field. We show that the phase of the external coherent field provides a gauge potential for the photon states. With a proper choice of the phase difference between the two coherent fields, the transport of a single photon can exhibit unity contrast in its transmissions for the two propagation directions. PMID:26565819

  16. SU(3) quantum interferometry with single-photon input pulses.

    PubMed

    Tan, Si-Hui; Gao, Yvonne Y; de Guise, Hubert; Sanders, Barry C

    2013-03-15

    We develop a framework for solving the action of a three-channel passive optical interferometer on single-photon pulse inputs to each channel using SU(3) group-theoretic methods, which can be readily generalized to higher-order photon-coincidence experiments. We show that features of the coincidence plots versus relative time delays of photons yield information about permanents, immanants, and determinants of the interferometer SU(3) matrix. PMID:25166532

  17. Enhancement of Single-Photon Sources with Metamaterials

    NASA Astrophysics Data System (ADS)

    Shalaginov, M. Y.; Bogdanov, S.; Vorobyov, V. V.; Lagutchev, A. S.; Kildishev, A. V.; Akimov, A. V.; Boltasseva, A.; Shalaev, V. M.

    2015-06-01

    Scientists are looking for new, breakthrough solutions that can greatly advance computing and networking systems. These solutions will involve quantum properties of matter and light as promised by the ongoing experimental and theoretical work in the areas of quantum computation and communication. Quantum photonics is destined to play a central role in the development of such technologies due to the high transmission capacity and outstanding low-noise properties of photonic information channels. Among the vital problems to be solved in this direction, are efficient generation and collection of single photons. One approach to tackle these problems is based on engineering emission properties of available single-photon sources using metamaterials. Metamaterials are artificially engineered structures with sub-wavelength features whose optical properties go beyond the limitations of conventional materials. As promising single-photon sources, we have chosen nitrogen-vacancy (NV) color centers in diamond, which are capable to operate stably in a single-photon regime at room temperature in a solid state environment. In this chapter, we report both theoretical and experimental studies of the radiation from a nanodiamond single NV center placed near a hyperbolic metamaterial (HMM). In particular, we derive the reduction of excited-state lifetime and the enhancement of collected single-photon emission rate and compare them with the experimental observations. These results could be of great impact for future integrated quantum sources, especially owing to a CMOS-compatible approach to HMM synthesis.

  18. Controlling single-photon transport with three-level quantum dots in photonic crystals

    NASA Astrophysics Data System (ADS)

    Yan, Cong-Hua; Jia, Wen-Zhi; Wei, Lian-Fu

    2014-03-01

    We investigate how to control single-photon transport along the photonic crystal waveguide with the recent experimentally demonstrated artificial atoms [i.e., Λ-type quantum dots (QDs)] [S. G. Carter et al., Nat. Photon. 7, 329 (2013), 10.1038/nphoton.2013.41] in an all-optical way. Adopting full quantum theory in real space, we analytically calculate the transport coefficients of single photons scattered by a Λ-type QD embedded in single- and two-mode photonic crystal cavities (PCCs), respectively. Our numerical results clearly show that the photonic transmission properties can be exactly manipulated by adjusting the coupling strengths of waveguide-cavity and QD-cavity interactions. Specifically, for the PCC with two degenerate orthogonal polarization modes coupled to a Λ-type QD with two degenerate ground states, we find that the photonic transmission spectra show three Rabi-splitting dips and the present system could serve as single-photon polarization beam splitters. The feasibility of our proposal with the current photonic crystal technique is also discussed.

  19. Dissipation-enabled efficient excitation transfer from a single photon to a single quantum emitter

    NASA Astrophysics Data System (ADS)

    Trautmann, N.; Alber, G.

    2016-05-01

    We propose a scheme for triggering a dissipation-dominated highly efficient excitation transfer from a single-photon wave packet to a single quantum emitter. This single-photon-induced optical pumping turns dominant dissipative processes, such as spontaneous photon emission by the emitter or cavity decay, into valuable tools for quantum information processing and quantum communication. It works for an arbitrarily shaped single-photon wave packet with sufficiently small bandwidth provided a matching condition is satisfied which balances the dissipative rates involved. Our scheme does not require additional laser pulses or quantum feedback and does not rely on high finesse optical resonators. In particular, it can be used to enhance significantly the coupling of a single photon to a single quantum emitter implanted in a one-dimensional waveguide or even in a free space scenario. We demonstrate the usefulness of our scheme for building a deterministic quantum memory and a deterministic frequency converter between photonic qubits of different wavelengths.

  20. Multiple-Event, Single-Photon Counting Imaging Sensor

    NASA Technical Reports Server (NTRS)

    Zheng, Xinyu; Cunningham, Thomas J.; Sun, Chao; Wang, Kang L.

    2011-01-01

    The single-photon counting imaging sensor is typically an array of silicon Geiger-mode avalanche photodiodes that are monolithically integrated with CMOS (complementary metal oxide semiconductor) readout, signal processing, and addressing circuits located in each pixel and the peripheral area of the chip. The major problem is its single-event method for photon count number registration. A single-event single-photon counting imaging array only allows registration of up to one photon count in each of its pixels during a frame time, i.e., the interval between two successive pixel reset operations. Since the frame time can t be too short, this will lead to very low dynamic range and make the sensor merely useful for very low flux environments. The second problem of the prior technique is a limited fill factor resulting from consumption of chip area by the monolithically integrated CMOS readout in pixels. The resulting low photon collection efficiency will substantially ruin any benefit gained from the very sensitive single-photon counting detection. The single-photon counting imaging sensor developed in this work has a novel multiple-event architecture, which allows each of its pixels to register as more than one million (or more) photon-counting events during a frame time. Because of a consequently boosted dynamic range, the imaging array of the invention is capable of performing single-photon counting under ultra-low light through high-flux environments. On the other hand, since the multiple-event architecture is implemented in a hybrid structure, back-illumination and close-to-unity fill factor can be realized, and maximized quantum efficiency can also be achieved in the detector array.

  1. Efficient photon counting and single-photon generation using resonant nonlinear optics

    SciTech Connect

    Johnsson, Mattias; Fleischhauer, Michael

    2003-06-01

    The behavior of an atomic double {lambda} system in the presence of a strong off-resonant classical field and a few-photon resonant quantum field is examined. It is shown that the system possesses properties that allow a single-photon state to be distilled from a multiphoton input wave packet. In addition, the system is also capable of functioning as an efficient photodetector discriminating between one- and two-photon wave packets with high efficiency.

  2. Total teleportation of a single-photon state

    SciTech Connect

    Humble, Travis S; Bennink, Ryan S; Grice, Warren P

    2008-01-01

    Recent demonstrations of teleportation have transferred quantum information encoded into either polarization or field-quadrature degrees of freedom (DOFs), but an outstanding question is how to simultaneously teleport quantum information encoded into multiple DOFs. We describe how the transverse-spatial, spectral and polarization states of a single photon can be simultaneously teleported using a pair of multimode, polarization-entangled photons derived from spontaneous parametric down-conversion. Furthermore, when the initial photon pair is maximally entangled in the spatial, spectral, and polarization DOFs then the photon s full quantum state can be reliably teleported using a Bell-state measurement based on sum-frequency generation.

  3. Single-photon frequency down-conversion experiment

    SciTech Connect

    Takesue, Hiroki

    2010-07-15

    We report a single-photon frequency down-conversion experiment. Using the difference frequency generation process in a periodically poled lithium niobate waveguide, we successfully observed the phase-preserved frequency down-conversion of a coherent pulse train with an average photon number per pulse of <1, from the 0.7 {mu}m visible wavelength band to the 1.3 {mu}m telecom band. We expect this technology to become an important tool for flexible photonic quantum networking, including the realization of quantum repeater systems over optical fiber using atom-photon entanglement sources for the visible wavelength bands.

  4. Total teleportation of a single-photon state

    NASA Astrophysics Data System (ADS)

    Humble, Travis S.; Bennink, Ryan S.; Grice, Warren P.

    2008-08-01

    Recent demonstrations of teleportation have transferred quantum information encoded into either polarization or fieldquadrature degrees of freedom (DOFs), but an outstanding question is how to simultaneously teleport quantum information encoded into multiple DOFs. We describe how the transverse-spatial, spectral and polarization states of a single photon can be simultaneously teleported using a pair of multimode, polarization-entangled photons derived from spontaneous parametric down-conversion. Furthermore, when the initial photon pair is maximally entangled in the spatial, spectral, and polarization DOFs then the photon's full quantum state can be reliably teleported using a Bell-state measurement based on sum-frequency generation.

  5. Single-photon quantum router with multiple output ports.

    PubMed

    Yan, Wei-Bin; Fan, Heng

    2014-01-01

    The routing capability is a requisite in quantum network. Although the quantum routing of signals has been investigated in various systems both in theory and experiment, the general form of quantum routing with many output terminals still needs to be explored. Here we propose a scheme to achieve the multi-channel quantum routing of the single photons in a waveguide-emitter system. The channels are composed by the waveguides and are connected by intermediate two-level emitters. By adjusting the intermediate emitters, the output channels of the input single photons can be controlled. This is demonstrated in the cases of one output channel, two output channels and the generic N output channels. The results show that the multi-channel quantum routing of single photons can be well achieved in the proposed system. This offers a scheme for the experimental realization of general quantum routing of single photons. PMID:24769619

  6. A microcontroller-based failsafe for single photon counting modules

    NASA Astrophysics Data System (ADS)

    Gordon, Matthew P.; Selvin, Paul R.

    2003-02-01

    Avalanche photodiode-based single photon counting modules (SPCMs) can be damaged by exposure to excessive light levels. A flexible and inexpensive failsafe is presented which has been shown to protect SPCMs from light levels far exceeding the damage threshold.

  7. Asymmetric architecture for heralded single-photon sources

    NASA Astrophysics Data System (ADS)

    Mazzarella, Luca; Ticozzi, Francesco; Sergienko, Alexander V.; Vallone, Giuseppe; Villoresi, Paolo

    2013-08-01

    Single-photon sources represent a fundamental building block for optical implementations of quantum information tasks ranging from basic tests of quantum physics to quantum communication and high-resolution quantum measurement. In this paper, in order to compare the effectiveness of different designs, we introduce a single-photon source performance index, based on the maximum probability of generating a single photon that still guarantees a given signal-to-noise ratio. We then investigate the performance of a multiplexed system based on asymmetric configuration of multiple heralded single-photon sources. The performance and scalability comparison with both currently existing multiple-source architectures and faint laser configurations reveals an advantage the proposed scheme offers in realistic scenarios. This analysis also provides insights on the potential of using such architectures for integrated implementation.

  8. Single-photon emission computed tomography (SPECT): Applications and potential

    SciTech Connect

    Holman, B.L.; Tumeh, S.S. )

    1990-01-26

    Single-photon emission computed tomography has received increasing attention as radiopharmaceuticals that reflect perfusion, metabolism, and receptor and cellular function have become widely available. Perfusion single-photon emission computed tomography of the brain provides functional information useful for the diagnosis and management of stroke, dementia, and epilepsy. Single-photon emission computed tomography has been applied to myocardial, skeletal, hepatic, and tumor scintigraphy, resulting in increased diagnostic accuracy over planar imaging because background activity and overlapping tissues interfere far less with activity from the target structure when tomographic techniques are used. Single-photon emission computed tomography is substantially less expensive and far more accessible than positron emission tomography and will become an increasingly attractive alternative for transferring the positron emission tomography technology to routine clinical use.

  9. Single Photon Avalanche Diodes: Towards the Large Bidimensional Arrays

    PubMed Central

    Privitera, Simona; Tudisco, Salvatore; Lanzanò, Luca; Musumeci, Francesco; Pluchino, Alessandro; Scordino, Agata; Campisi, Angelo; Cosentino, Luigi; Finocchiaro, Paolo; Condorelli, Giovanni; Mazzillo, Massimo; Lombardo, Salvo; Sciacca, Emilio

    2008-01-01

    Single photon detection is one of the most challenging goals of photonics. In recent years, the study of ultra-fast and/or low-intensity phenomena has received renewed attention from the academic and industrial communities. Intense research activity has been focused on bio-imaging applications, bio-luminescence, bio-scattering methods, and, more in general, on several applications requiring high speed operation and high timing resolution. In this paper we present design and characterization of bi-dimensional arrays of a next generation of single photon avalanche diodes (SPADs). Single photon sensitivity, dark noise, afterpulsing and timing resolution of the single SPAD have been examined in several experimental conditions. Moreover, the effects arising from their integration and the readout mode have also been deeply investigated.

  10. Entanglement of a scattered single photon with an atom

    SciTech Connect

    Guo Rui; Guo Hong

    2006-01-15

    A single photon which is initially uncorrelated with an atom will evolve to be entangled with the atom on their continuous kinetic variables in the process of resonant scattering. We find the relations between the entanglement and their physical control parameters, which indicates that high entanglement can be reached by broadening the scale of the atomic wave or squeezing the linewidth of the incident single-photon pulse.

  11. Quantum nanophotonics: Controlling a photon with a single spin

    NASA Astrophysics Data System (ADS)

    Waks, Edo

    The implementation of quantum network and distributive quantum computation replies on strong interactions between stationary matter qubits and flying photons. The spin of a single electron confined in a quantum dot is considered as a promising matter qubit as it possesses microsecond coherence time and allows picosecond timescale control using optical pulses. The quantum dot spin can also interact with a photon by controlling the optical response of a strongly coupled cavity. In this talk I will discuss our recent work on an experimental realization of a spin-photon quantum phase switch using a single spin in a quantum dot strongly coupled to a photonic crystal cavity. We show large modulation of the cavity reflection spectrum by manipulating the spin states of the quantum dot, which enables us to control the quantum state of a reflected photon. We also show the complementary effect where the presence of a single photon switches the quantum state of the spin. The reported spin-photon quantum phase operation can switch spin or photon states in picoseconds timescale, representing an important step towards GHz semiconductor based quantum logic devices on-a-chip and solid-state implementations of quantum networks. Shuo Sun, Hyochul Kim, Glenn Solomon, co-authors.

  12. Photon pair source via two coupling single quantum emitters

    NASA Astrophysics Data System (ADS)

    Peng, Yong-Gang; Zheng, Yu-Jun

    2015-10-01

    We study the two coupling two-level single molecules driven by an external field as a photon pair source. The probability of emitting two photons, P2, is employed to describe the photon pair source quality in a short time, and the correlation coefficient RAB is employed to describe the photon pair source quality in a long time limit. The results demonstrate that the coupling single quantum emitters can be considered as a stable photon pair source. Project supported by the National Natural Science Foundation of China (Grand Nos. 91021009, 21073110, and 11374191), the Natural Science Foundation of Shandong Province, China (Grant No. ZR2013AQ020), the Postdoctoral Science Foundation of China (Grant No. 2013M531584), the Doctoral Program of Higher Education of China (Grant Nos. 20130131110005 and 20130131120006), and the Taishan Scholarship Project of Shandong Province, China.

  13. Determination of single gamma photon fraction of 124I PET

    NASA Astrophysics Data System (ADS)

    Kim, Jin Su; Ram Yu, A.

    2015-03-01

    124I has a half-life of 4.2 days, which makes it suitable for imaging over several days along uptake and washout phases. However, it has a low positron branching ratio (23%), because high-energy gamma photons (602 to 1,691 keV), which degrade image quality, are emitted in cascade with positrons. In this study, we measured the single gamma photon fraction of 124I on Inveon PET scanner. Methods: to measure the single gamma photon fraction (SGF) of 124I, we measured the sensitivities of 124I and 18F from energy windows. The spill over ratios (SORs) of 124I were measured to assess the effect of single gamma photons fractions. Results: the SGF were 31%, 24%, and 3% in 0350 ~ 75, 0350 ~ 65, and 0350~ 55 keV, respectively. After single gamma corrections the SOR was decreased by 13% point. Conclusion: the proposed method for measuring the single gamma photons fraction of 124I will be useful to correct the single gamma photons from 124I PET. This information would also be useful to quantify the 124I PET.

  14. Efficient room-temperature source of polarized single photons

    SciTech Connect

    Lukishova, Svetlana G.; Boyd, Robert W.; Stroud, Carlos R.

    2007-08-07

    An efficient technique for producing deterministically polarized single photons uses liquid-crystal hosts of either monomeric or oligomeric/polymeric form to preferentially align the single emitters for maximum excitation efficiency. Deterministic molecular alignment also provides deterministically polarized output photons; using planar-aligned cholesteric liquid crystal hosts as 1-D photonic-band-gap microcavities tunable to the emitter fluorescence band to increase source efficiency, using liquid crystal technology to prevent emitter bleaching. Emitters comprise soluble dyes, inorganic nanocrystals or trivalent rare-earth chelates.

  15. Multiboson Correlation Interferometry with Arbitrary Single-Photon Pure States.

    PubMed

    Tamma, Vincenzo; Laibacher, Simon

    2015-06-19

    We provide a compact full description of multiboson correlation measurements of arbitrary order N in passive linear interferometers with arbitrary input single-photon pure states. This allows us to physically analyze the novel problem of multiboson correlation sampling at the output of random linear interferometers. Our results also describe general multiboson correlation landscapes for an arbitrary number of input single photons and arbitrary interferometers. In particular, we use two different schemes to demonstrate, respectively, arbitrary-order quantum beat interference and 100% visibility entanglement correlations even for input photons distinguishable in their frequencies. PMID:26196976

  16. A versatile source of single photons for quantum information processing

    NASA Astrophysics Data System (ADS)

    Förtsch, Michael; Fürst, Josef U.; Wittmann, Christoffer; Strekalov, Dmitry; Aiello, Andrea; Chekhova, Maria V.; Silberhorn, Christine; Leuchs, Gerd; Marquardt, Christoph

    2013-05-01

    The generation of high-quality single-photon states with controllable narrow spectral bandwidths and central frequencies is key to facilitate efficient coupling of any atomic system to non-classical light fields. Such an interaction is essential in numerous experiments for fundamental science and applications in quantum communication and information processing, as well as in quantum metrology. Here we implement a fully tunable, narrow-band and efficient single-photon source based on a whispering gallery mode resonator. Our disk-shaped, monolithic and intrinsically stable resonator is made of lithium niobate and supports a cavity-assisted spontaneous parametric down-conversion process. The generated photon pairs are emitted into two highly tunable resonator modes. We verify wavelength tuning over 100 nm of both modes with controllable bandwidth between 7.2 and 13 MHz. Heralding of single photons yields anti-bunching with g(2)(0)<0.2.

  17. Witnessing trustworthy single-photon entanglement with local homodyne measurements.

    PubMed

    Morin, Olivier; Bancal, Jean-Daniel; Ho, Melvyn; Sekatski, Pavel; D'Auria, Virginia; Gisin, Nicolas; Laurat, Julien; Sangouard, Nicolas

    2013-03-29

    Single-photon entangled states, i.e., states describing two optical paths sharing a single photon, constitute the simplest form of entanglement. Yet they provide a valuable resource in quantum information science. Specifically, they lie at the heart of quantum networks, as they can be used for quantum teleportation, swapped, and purified with linear optics. The main drawback of such entanglement is the difficulty in measuring it. Here, we present and experimentally test an entanglement witness allowing one to say whether a given state is path entangled and also that entanglement lies in the subspace, where the optical paths are each filled with one photon at most, i.e., refers to single-photon entanglement. It uses local homodyning only and relies on no assumption about the Hilbert space dimension of the measured system. Our work provides a simple and trustworthy method for verifying the proper functioning of future quantum networks. PMID:23581297

  18. Macroscopic rotation of photon polarization induced by a single spin

    PubMed Central

    Arnold, Christophe; Demory, Justin; Loo, Vivien; Lemaître, Aristide; Sagnes, Isabelle; Glazov, Mikhaïl; Krebs, Olivier; Voisin, Paul; Senellart, Pascale; Lanco, Loïc

    2015-01-01

    Entangling a single spin to the polarization of a single incoming photon, generated by an external source, would open new paradigms in quantum optics such as delayed-photon entanglement, deterministic logic gates or fault-tolerant quantum computing. These perspectives rely on the possibility that a single spin induces a macroscopic rotation of a photon polarization. Such polarization rotations induced by single spins were recently observed, yet limited to a few 10−3 degrees due to poor spin–photon coupling. Here we report the enhancement by three orders of magnitude of the spin–photon interaction, using a cavity quantum electrodynamics device. A single hole spin in a semiconductor quantum dot is deterministically coupled to a micropillar cavity. The cavity-enhanced coupling between the incoming photons and the solid-state spin results in a polarization rotation by ±6° when the spin is optically initialized in the up or down state. These results open the way towards a spin-based quantum network. PMID:25687134

  19. A silicon carbide room-temperature single-photon source.

    PubMed

    Castelletto, S; Johnson, B C; Ivády, V; Stavrias, N; Umeda, T; Gali, A; Ohshima, T

    2014-02-01

    Over the past few years, single-photon generation has been realized in numerous systems: single molecules, quantum dots, diamond colour centres and others. The generation and detection of single photons play a central role in the experimental foundation of quantum mechanics and measurement theory. An efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing. Here we report the identification and formation of ultrabright, room-temperature, photostable single-photon sources in a device-friendly material, silicon carbide (SiC). The source is composed of an intrinsic defect, known as the carbon antisite-vacancy pair, created by carefully optimized electron irradiation and annealing of ultrapure SiC. An extreme brightness (2×10(6) counts s(-1)) resulting from polarization rules and a high quantum efficiency is obtained in the bulk without resorting to the use of a cavity or plasmonic structure. This may benefit future integrated quantum photonic devices. PMID:24240243

  20. Macroscopic rotation of photon polarization induced by a single spin.

    PubMed

    Arnold, Christophe; Demory, Justin; Loo, Vivien; Lemaître, Aristide; Sagnes, Isabelle; Glazov, Mikhaïl; Krebs, Olivier; Voisin, Paul; Senellart, Pascale; Lanco, Loïc

    2015-01-01

    Entangling a single spin to the polarization of a single incoming photon, generated by an external source, would open new paradigms in quantum optics such as delayed-photon entanglement, deterministic logic gates or fault-tolerant quantum computing. These perspectives rely on the possibility that a single spin induces a macroscopic rotation of a photon polarization. Such polarization rotations induced by single spins were recently observed, yet limited to a few 10(-3) degrees due to poor spin-photon coupling. Here we report the enhancement by three orders of magnitude of the spin-photon interaction, using a cavity quantum electrodynamics device. A single hole spin in a semiconductor quantum dot is deterministically coupled to a micropillar cavity. The cavity-enhanced coupling between the incoming photons and the solid-state spin results in a polarization rotation by ± 6° when the spin is optically initialized in the up or down state. These results open the way towards a spin-based quantum network. PMID:25687134

  1. A single-photon fluorescence and multi-photon spectroscopic study of atherosclerotic lesions

    NASA Astrophysics Data System (ADS)

    Smith, Michael S. D.; Ko, Alex C. T.; Ridsdale, Andrew; Schattka, Bernie; Pegoraro, Adrian; Hewko, Mark D.; Shiomi, Masashi; Stolow, Albert; Sowa, Michael G.

    2009-06-01

    In this study we compare the single-photon autofluorescence and multi-photon emission spectra obtained from the luminal surface of healthy segments of artery with segments where there are early atherosclerotic lesions. Arterial tissue was harvested from atherosclerosis-prone WHHL-MI rabbits (Watanabe heritable hyperlipidemic rabbit-myocardial infarction), an animal model which mimics spontaneous myocardial infarction in humans. Single photon fluorescence emission spectra of samples were acquired using a simple spectrofluorometer set-up with 400 nm excitation. Samples were also investigated using a home built multi-photon microscope based on a Ti:sapphire femto-second oscillator. The excitation wavelength was set at 800 nm with a ~100 femto-second pulse width. Epi-multi-photon spectroscopic signals were collected through a fibre-optics coupled spectrometer. While the single-photon fluorescence spectra of atherosclerotic lesions show minimal spectroscopic difference from those of healthy arterial tissue, the multi-photon spectra collected from atherosclerotic lesions show marked changes in the relative intensity of two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) signals when compared with those from healthy arterial tissue. The observed sharp increase of the relative SHG signal intensity in a plaque is in agreement with the known pathology of early lesions which have increased collagen content.

  2. The ionization rate inversion of H? induced by the single and double UV photon(s)

    NASA Astrophysics Data System (ADS)

    He, Pei-Lun; He, Feng

    2013-11-01

    The ionization of H? in the strong UV laser pulse is studied by numerically solving the time-dependent Schrödinger equation. In analogy to Young's double-slit interference, the ionized electron originating from two nuclei will constructively, or destructively interfere, depending on the UV frequencies. The fluctuation of the ionization rate as a function of the laser frequency is observed. The destructive interference suppresses the single-photon ionization rate, so that the double-photon ionization rate can be larger than the single-photon ionization rate. When such an ionization-rate inversion happens, the electron momentum spectra splits into several peaks.

  3. Localised excitation of a single photon source by a nanowaveguide.

    PubMed

    Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; De Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

    2016-01-01

    Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10(-4) only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system. PMID:26822999

  4. Localised excitation of a single photon source by a nanowaveguide

    NASA Astrophysics Data System (ADS)

    Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; de Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

    2016-01-01

    Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10-4 only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system.

  5. Localised excitation of a single photon source by a nanowaveguide

    PubMed Central

    Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; De Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

    2016-01-01

    Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10−4 only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system. PMID:26822999

  6. Ultrafast single photon emitting quantum photonic structures based on a nano-obelisk

    PubMed Central

    Kim, Je-Hyung; Ko, Young-Ho; Gong, Su-Hyun; Ko, Suk-Min; Cho, Yong-Hoon

    2013-01-01

    A key issue in a single photon source is fast and efficient generation of a single photon flux with high light extraction efficiency. Significant progress toward high-efficiency single photon sources has been demonstrated by semiconductor quantum dots, especially using narrow bandgap materials. Meanwhile, there are many obstacles, which restrict the use of wide bandgap semiconductor quantum dots as practical single photon sources in ultraviolet-visible region, despite offering free space communication and miniaturized quantum information circuits. Here we demonstrate a single InGaN quantum dot embedded in an obelisk-shaped GaN nanostructure. The nano-obelisk plays an important role in eliminating dislocations, increasing light extraction, and minimizing a built-in electric field. Based on the nano-obelisks, we observed nonconventional narrow quantum dot emission and positive biexciton binding energy, which are signatures of negligible built-in field in single InGaN quantum dots. This results in efficient and ultrafast single photon generation in the violet color region. PMID:23828558

  7. Engineering single photon emitters by ion implantation in diamond.

    PubMed

    Naydenov, B; Kolesov, R; Batalov, A; Meijer, J; Pezzagna, S; Rogalla, D; Jelezko, F; Wrachtrup, J

    2009-11-01

    Diamond provides unique technological platform for quantum technologies including quantum computing and communication. Controlled fabrication of optically active defects is a key element for such quantum toolkit. Here we report the production of single color centers emitting in the blue spectral region by high energy implantation of carbon ions. We demonstrate that single implanted defects show sub-poissonian statistics of the emitted photons and can be explored as single photon source in quantum cryptography. Strong zero phonon line at 470.5 nm allows unambiguous identification of this defect as interstitial-related TR12 color center. PMID:19956415

  8. Superconducting-nanowire single-photon-detector linear array

    NASA Astrophysics Data System (ADS)

    Zhao, Qingyuan; McCaughan, Adam; Bellei, Francesco; Najafi, Faraz; De Fazio, Domenico; Dane, Andrew; Ivry, Yachin; Berggren, Karl K.

    2013-09-01

    We designed, fabricated, and tested a one-dimensional array of superconducting-nanowire single-photon detectors, integrated with on-chip inductors and resistors. The architecture is suitable for monolithic integration on a single chip operated in a cryogenic environment, and inherits the characteristics of individual superconducting-nanowire single-photon detectors. We demonstrated a working array with four pixels showing position discrimination and a timing jitter of 124 ps. The electronic crosstalk between the pixels in the array was negligible.

  9. Quantum interference of independently generated telecom-band single photons

    SciTech Connect

    Patel, Monika; Altepeter, Joseph B.; Huang, Yu-Ping; Oza, Neal N.; Kumar, Prem

    2014-12-04

    We report on high-visibility quantum interference of independently generated telecom O-band (1310 nm) single photons using standard single-mode fibers. The experimental data are shown to agree well with the results of simulations using a comprehensive quantum multimode theory without the need for any fitting parameter.

  10. A single-molecule approach to ZnO defect studies: Single photons and single defects

    SciTech Connect

    Jungwirth, N. R.; Pai, Y. Y.; Chang, H. S.; MacQuarrie, E. R.; Nguyen, K. X.; Fuchs, G. D.

    2014-07-28

    Investigations that probe defects one at a time offer a unique opportunity to observe properties and dynamics that are washed out of ensemble measurements. Here, we present confocal fluorescence measurements of individual defects in ZnO nanoparticles and sputtered films that are excited with sub-bandgap energy light. Photon correlation measurements yield both antibunching and bunching, indicative of single-photon emission from isolated defects that possess a metastable shelving state. The single-photon emission is in the range of ∼560–720 nm and typically exhibits two broad spectral peaks separated by ∼150 meV. The excited state lifetimes range from 1 to 13 ns, consistent with the finite-size and surface effects of nanoparticles and small grains. We also observe discrete jumps in the fluorescence intensity between a bright state and a dark state. The dwell times in each state are exponentially distributed and the average dwell time in the bright (dark) state does (may) depend on the power of the exciting laser. Taken together, our measurements demonstrate the utility of a single-molecule approach to semiconductor defect studies and highlight ZnO as a potential host material for single-defect based applications.

  11. Development of a GSO positron/single-photon imaging detector

    NASA Astrophysics Data System (ADS)

    Yamamoto, S.; Matsumoto, K.; Senda, M.

    2006-01-01

    We have developed and tested a GSO (gadolinium oxyorthosilicate) position-sensitive gamma detector which can be used with positron and single-photon radionuclides for imaging breast cancer or sentinel lymph node detection. Because GSO has a relatively good energy resolution for annihilation gammas as well as low energy gamma photons, and does not contain any natural radioisotopes, it can be used for positron imaging and lower energy single-photon imaging. The imaging detector consists of a GSO block, 2 inch square multi-channel position-sensitive photo-multiplier tube (PSPMT), and associated electronics. The size of a single GSO element was 2.9 mm × 2.9 mm × 20 mm and these elements were arranged into 15 × 15 matrixes to form a block that was optically coupled to the PSPMT. It was possible to separate all GSO crystals into a two-dimensional position histogram for annihilation gammas (511 keV) and low energy gamma photons (122 keV). The typical energy resolution was 24% FWHM and 37% FWHM for 511 keV and 122 keV gamma photons, respectively. For the positron imaging, coincidence between the imaging detector and a single gamma probe is measured. For the single-photon imaging, a tungsten collimator is mounted in front of the imaging detector. With this configuration, it was possible to image both positron radionuclides and low energy single-photon radionuclides. We measured spatial resolution and sensitivity as well as image quality of the developed imaging detector. Results indicated that the developed imaging detector has the potential to be a new and useful instrument for nuclear medicine.

  12. SIMULTANEOUS TELEPORTATION OF MULTIPLE SINGLE-PHOTON DEGREES OF FREEDOM

    SciTech Connect

    Humble, Travis S; Bennink, Ryan S; Grice, Warren P

    2011-01-01

    We report how quantum information encoded into multiple photonic degrees of freedom may be simultaneously teleported using a single, common physical process. The application of teleportation to the complete quantum state of a photon, i.e., the spectral, spatial, and polarization component states, permits the full photonic Hilbert space to be used for encoding information while simultaneously enabling subspaces to be addressed individually, e.g., for quantum information processing. We analyze the feasibility of teleporting the full quantum state through numerical analysis of the fidelity under nominal experimental conditions and for different types of input states, e.g., single-photon states that are separable and entangled in the physical degrees of freedom.

  13. Highly efficient source for indistinguishable single photons of controlled shape

    NASA Astrophysics Data System (ADS)

    Nisbet-Jones, Peter B. R.; Dilley, Jerome; Ljunggren, Daniel; Kuhn, Axel

    2011-10-01

    We demonstrate a straightforward implementation of a push-button like single-photon source, which is based on a strongly coupled atom-cavity system. The device operates intermittently for periods of up to 100 μs, with single-photon repetition rates of 1.0 MHz and an efficiency of 60%. Atoms are loaded into the cavity using an atomic fountain, with the upper turning point near the cavity's mode centre. This ensures long interaction times without any disturbances induced by trapping potentials. The latter is the key to reaching deterministic efficiencies as high as obtained in probabilistic photon-heralding schemes. The price to pay is the random loading of atoms into the cavity and the resulting intermittency. However, for all practical purposes, this has a negligible impact as an individual atom may emit up to 100 successive photons.

  14. Single Photon Interference with Spontaneous Parametric Downconversion Source

    NASA Astrophysics Data System (ADS)

    Alexander, Preston; Baldwin, Scott; McCracken, S. Blane; Smith, R. Seth

    2015-04-01

    During the past two years, a Quantum Optics Laboratory was constructed and tested at Francis Marion University. A spontaneous parametric downconversion source was used to create pairs of correlated photons for use in single photon tests of quantum mechanics. In this experiment, single photon interference was demonstrated by using a spontaneous parametric downconversion source. The two beams emanating from the downconversion crystal are referred to as the signal and idler beams. Detector A was placed in front the idler beam. The signal beam was sent to a polarization interferometer that was followed by a 50/50 beam splitter. The reflected and transmitted beams were incident on Detectors B and B'. By observing the presence or absence of coincidences, it was possible to demonstrate both particle and wave behaviors for light. In particular, if individual photons are passed through a polarization interferometer, it was shown that they will interfere with themselves. The details of the experimental setup and the results will be presented.

  15. Plasmonic nanoantenna based triggered single-photon source

    NASA Astrophysics Data System (ADS)

    Straubel, J.; Filter, R.; Rockstuhl, C.; Słowik, K.

    2016-05-01

    Highly integrated single-photon sources are key components in future quantum-optical circuits. Whereas the probabilistic generation of single photons can routinely be done by now, their triggered generation is a much greater challenge. Here, we describe the triggered generation of single photons in a hybrid plasmonic device. It consists of a lambda-type quantum emitter coupled to a multimode optical nanoantenna. For moderate interaction strengths between the subsystems, the description of the quantum optical evolution can be simplified by an adiabatic elimination of the electromagnetic fields of the nanoantenna modes. This leads to an insightful analysis of the emitter's dynamics, entails the opportunity to understand the physics of the device, and to identify parameter regimes for a desired operation. Even though the approach presented in this work is general, we consider a simple exemplary design of a plasmonic nanoantenna, made of two silver nanorods, suitable for triggered generation of single photons. The investigated device realizes single photons, triggered, potentially at high rates, and using low device volumes.

  16. Single-Photon Nonlinear Optics with Graphene Plasmons

    NASA Astrophysics Data System (ADS)

    Gullans, M.; Chang, D. E.; Koppens, F. H. L.; de Abajo, F. J. García; Lukin, M. D.

    2013-12-01

    We show that it is possible to realize significant nonlinear optical interactions at the few photon level in graphene nanostructures. Our approach takes advantage of the electric field enhancement associated with the strong confinement of graphene plasmons and the large intrinsic nonlinearity of graphene. Such a system could provide a powerful platform for quantum nonlinear optical control of light. As an example, we consider an integrated optical device that exploits this large nonlinearity to realize a single photon switch.

  17. Cooperative single-photon subradiant states

    NASA Astrophysics Data System (ADS)

    Jen, H. H.; Chang, M.-S.; Chen, Y.-C.

    2016-07-01

    We propose a set of subradiant states which can be prepared and detected in a one-dimensional optical lattice. We find that the decay rates are highly dependent on the spatial phases imprinted on the atomic chain, which allows systematic investigations of the subradiance in fluorescence experiments. The time evolution of these states can have a long decay time where up to 100 ms of lifetime is predicted for 100 atoms. They can also show decayed Rabi-like oscillations with a beating frequency determined by the difference of the cooperative Lamb shift in the subspace. Experimental requirements are also discussed for practical implementation of the subradiant states. Our proposal provides a scheme for quantum storage of photons in arrays of two-level atoms through the preparation and detection of subradiant states, which offers opportunities for quantum many-body state preparation and quantum information processing in optical lattices.

  18. Study of narrowband single photon emitters in polycrystalline diamond films

    SciTech Connect

    Sandstrom, Russell G.; Shimoni, Olga; Martin, Aiden A.; Aharonovich, Igor

    2014-11-03

    Quantum information processing and integrated nanophotonics require robust generation of single photon emitters on demand. In this work, we demonstrate that diamond films grown on a silicon substrate by microwave plasma chemical vapor deposition can host bright, narrowband single photon emitters in the visible—near infra-red spectral range. The emitters possess fast lifetime (∼several ns), absolute photostability, and exhibit full polarization at excitation and emission. Pulsed and continuous laser excitations confirm their quantum behaviour at room temperature, while low temperature spectroscopy is performed to investigate inhomogeneous broadening. Our results advance the knowledge of solid state single photon sources and open pathways for their practical implementation in quantum communication and quantum information processing.

  19. Photon Cascade from a Single Crystal Phase Nanowire Quantum Dot.

    PubMed

    Bouwes Bavinck, Maaike; Jöns, Klaus D; Zieliński, Michal; Patriarche, Gilles; Harmand, Jean-Christophe; Akopian, Nika; Zwiller, Val

    2016-02-10

    We report the first comprehensive experimental and theoretical study of the optical properties of single crystal phase quantum dots in InP nanowires. Crystal phase quantum dots are defined by a transition in the crystallographic lattice between zinc blende and wurtzite segments and therefore offer unprecedented potential to be controlled with atomic layer accuracy without random alloying. We show for the first time that crystal phase quantum dots are a source of pure single-photons and cascaded photon-pairs from type II transitions with excellent optical properties in terms of intensity and line width. We notice that the emission spectra consist often of two peaks close in energy, which we explain with a comprehensive theory showing that the symmetry of the system plays a crucial role for the hole levels forming hybridized orbitals. Our results state that crystal phase quantum dots have promising quantum optical properties for single photon application and quantum optics. PMID:26806321

  20. Diagnosis of dementia with single photon emission computed tomography

    SciTech Connect

    Jagust, W.J.; Budinger, T.F.; Reed, B.R.

    1987-03-01

    Single photon emission computed tomography is a practical modality for the study of physiologic cerebral activity in vivo. We utilized single photon emission computed tomography and N-isopropyl-p-iodoamphetamine iodine 123 to evaluate regional cerebral blood flow in nine patients with Alzheimer's disease (AD), five healthy elderly control subjects, and two patients with multi-infarct dementia. We found that all subjects with AD demonstrated flow deficits in temporoparietal cortex bilaterally, and that the ratio of activity in bilateral temporoparietal cortex to activity in the whole slice allowed the differentiation of all patients with AD from both the controls and from the patients with multi-infarct dementia. Furthermore, this ratio showed a strong correlation with disease severity in the AD group. Single photon emission computed tomography appears to be useful in the differential diagnosis of dementia and reflects clinical features of the disease.

  1. Experimental quasi-single-photon transmission from satellite to earth.

    PubMed

    Yin, Juan; Cao, Yuan; Liu, Shu-Bin; Pan, Ge-Sheng; Wang, Jin-Hong; Yang, Tao; Zhang, Zhong-Ping; Yang, Fu-Min; Chen, Yu-Ao; Peng, Cheng-Zhi; Pan, Jian-Wei

    2013-08-26

    Free-space quantum communication with satellites opens a promising avenue for global secure quantum network and large-scale test of quantum foundations. Recently, numerous experimental efforts have been carried out towards this ambitious goal. However, one essential step--transmitting single photons from the satellite to the ground with high signal-to-noise ratio (SNR) at realistic environments--remains experimental challenging. Here, we report a direct experimental demonstration of the satellite-ground transmission of a quasi-single-photon source. In the experiment, single photons (~0.85 photon per pulse) are generated by reflecting weak laser pulses back to earth with a cube-corner retro-reflector on the satellite CHAMP, collected by a 600-mm diameter telescope at the ground station, and finally detected by single-photon counting modules after 400-km free-space link transmission. With the help of high accuracy time synchronization, narrow receiver field-of-view and high-repetition-rate pulses (76 MHz), a SNR of better than 16:1 is obtained, which is sufficient for a secure quantum key distribution. Our experimental results represent an important step towards satellite-ground quantum communication. PMID:24105550

  2. Quantum dots in photonic crystals: from quantum information processing to single photon nonlinear optics

    NASA Astrophysics Data System (ADS)

    Vuckovic, Jelena

    2009-05-01

    Quantum dots in photonic crystals are interesting both as a testbed for fundamental cavity quantum electrodynamics (QED) experiments, as well as a platform for quantum and classical information processing. Quantum dot-photonic crystal cavity QED has been probed both in photoluminescence and coherently, by resonant light scattering from such a system [1]. In the latter case, both intensity and photon statistics of the reflected beam have been analyzed as a function of wavelength, leading to observation of effects such as photon blockade and photon induced tunneling - for the first time in solid state [2]. The system has also been employed to achieve a controlled phase and amplitude modulation between two modes of light at the single photon level [3] - nonlinearity observed so far only in atomic physics systems. These demonstrations lie at the core of a number of proposals for quantum information processing, and could also be employed to build novel devices, such as optical switches controlled at a single photon level. [4pt] [1] Dirk Englund, Andrei Faraon, Ilya Fushman, Nick Stoltz, Pierre Petroff, and Jelena Vuckovic, ``Controlling cavity reflectivity with a single quantum dot," Nature ,ol. 450, No. 7171, pp. 857-861, December 2007[0pt] [2] Andrei Faraon, Ilya Fushman, Dirk Englund, Nick Stoltz, Pierre Petroff, and Jelena Vuckovic, ``Coherent generation of nonclassical light on a chip via photon-induced tunneling and blockade," Nature Physics ,ol. 4, pp. 859 - 863 (2008)[0pt] [3] Ilya Fushman, Dirk Englund, Andrei Faraon, Nick Stoltz, Pierre Petroff, and Jelena Vuckovic, ``Controlled phase shift with a single quantum dot," Science ,ol. 320, number 5877, pp. 769-772 ( 2008)

  3. Single-photon interference experiment for high schools

    NASA Astrophysics Data System (ADS)

    Bondani, Maria

    2014-07-01

    We follow the reductio ad absurdum reasoning described in the book "Sneaking a Look at God's Cards" by Giancarlo Ghirardi to demonstrate the wave-particle duality of light in a Mach-Zehnder interferometric setup analog to the conventional Young double-slit experiment. We aim at showing the double nature of light by measuring the existence of interference fringes down to the single-photon level. The setup includes a strongly attenuated laser, polarizing beam splitters, half-waveplates, polarizers and single-photon detectors.

  4. Investigation of Hamamatsu H8500 phototubes as single photon detectors

    NASA Astrophysics Data System (ADS)

    Montgomery, R. A.; Hoek, M.; Lucherini, V.; Mirazita, M.; Orlandi, A.; Anefalos Pereira, S.; Pisano, S.; Rossi, P.; Viticchiè, A.; Witchger, A.

    2015-08-01

    We have investigated the response of a significant sample of Hamamatsu H8500 MultiAnode PhotoMultiplier Tubes (MAPMTs) as single photon detectors, in view of their use in a ring imaging Cherenkov counter for the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility. For this, a laser working at 407.2 nm wavelength was employed. The sample is divided equally into standard window type, with a spectral response in the visible light region, and UV-enhanced window type MAPMTs. The studies confirm the suitability of these MAPMTs for single photon detection in such a Cherenkov imaging application.

  5. Effective image filtration of pediatric single photon emission tomograms

    SciTech Connect

    Gilday, D.L.; Green, M.D.; Puntillo, R.; Ash, J.M.

    1984-01-01

    Single Photon Emission Computed Tomography (SPECT) in children suffers from relatively poor photon statistics due to the lower radiopharmaceutical dose when compared with adults. Consequently, the authors have made a major effort to improve the resultant tomographic images. The authors compared the effect that different measurements had on the basic reconstruction. The baseline study was a reconstruction with an internal filter appropriate to the planar image's photon density. The first enhancement was to three dimensionally filter planar images prior to reconstructing with an internal ''high resolution'' filter. The second was to apply three dimensional filter to the images which were reconstructed with an internal ''high resolution'' filter. The filtration and reconstruction were performed on both MDS-A/sup 2/, A/sup 3/ and GE Star computers. The results showed that planar images which were of poor photon flux produced much better reconstructions when pre-filtered, whereas the difference was not nearly so dramatic with high photon flux studies. Therefore, the authors recommend routine pre-reconstruction three dimensional filtering on all SPECT studies, especially those of poor photon flux. In fact in some very low photon flux 24 hour CSF, Thallium and Gallium studies, it was only possible to interpret those images when pre-filtered first.

  6. Single-Photon Transistor Using a Förster Resonance

    NASA Astrophysics Data System (ADS)

    Tiarks, Daniel; Baur, Simon; Schneider, Katharina; Duerr, Stephan; Rempe, Gerhard

    2015-05-01

    An all-optical transistor is a device in which a gate light pulse switches the transmission of a target light pulse with a gain above unity. The gain quantifies the change of the transmitted target photon number per incoming gate photon. We study the quantum limit of one incoming gate photon and observe a gain of 20. The gate pulse is stored as a Rydberg excitation in an ultracold gas. The transmission of the subsequent target pulse is suppressed by Rydberg blockade which is enhanced by a Förster resonance. The detected target photons reveal in a single shot with a fidelity above 0.86 whether a Rydberg excitation was created during the gate pulse. The gain offers the possibility to distribute the transistor output to the inputs of many transistors, thus making complex computational tasks possible.

  7. Single-Photon Switch Based on Rydberg Blockade

    NASA Astrophysics Data System (ADS)

    Baur, Simon; Tiarks, Daniel; Rempe, Gerhard; Duerr, Stephan

    2015-05-01

    All-optical switching is a technique in which a gate light pulse changes the transmission of a target light pulse without the detour via electronic signal processing. We take this to the quantum regime, where the incoming gate light pulse contains only one photon on average. The gate pulse is stored as a Rydberg excitation in an ultracold atomic gas using electromagnetically induced transparency. Rydberg blockade suppresses the transmission of the subsequent target pulse. Finally, the stored gate photon can be retrieved. A retrieved photon heralds successful storage. The corresponding postselected subensemble shows a relative transmission of 0.05. The single-photon switch offers many interesting perspectives ranging from quantum communication to quantum information processing.

  8. Single-Photon Transistor Using a Förster Resonance

    NASA Astrophysics Data System (ADS)

    Tiarks, Daniel; Baur, Simon; Schneider, Katharina; Dürr, Stephan; Rempe, Gerhard

    2014-08-01

    An all-optical transistor is a device in which a gate light pulse switches the transmission of a target light pulse with a gain above unity. The gain quantifies the change of the transmitted target photon number per incoming gate photon. We study the quantum limit of one incoming gate photon and observe a gain of 20. The gate pulse is stored as a Rydberg excitation in an ultracold gas. The transmission of the subsequent target pulse is suppressed by Rydberg blockade, which is enhanced by a Förster resonance. The detected target photons reveal in a single shot with a fidelity above 0.86 whether a Rydberg excitation was created during the gate pulse. The gain offers the possibility to distribute the transistor output to the inputs of many transistors, thus making complex computational tasks possible.

  9. A compact photonic crystal micro-cavity on a single-mode lithium niobate photonic wire

    NASA Astrophysics Data System (ADS)

    Cai, Lutong; Zhang, Shaomei; Hu, Hui

    2016-03-01

    The properties of the guided modes, including the single-mode conditions and the coupling of different polarized modes in the single-crystal lithium niobate photonic wires, were analyzed in detail. One-dimensional photonic crystal micro-cavities with several different patterns, which could be used as an ultra-compact optical filter, were designed and simulated in order to get high transmission at the resonant wavelength and the best preferment. The designed structure, with the whole size of 6.5 × 0.7 μm2, was fabricated on a single-mode photonic wire. A measured peak transmission of 0.34 at 1400 nm, an extinction ratio of 12.5 dB and a Q factor of 156 were obtained. The measured transmission spectrum was basically consistent with the simulation, although a slight shift of resonant wavelength occurred due to the fabrication errors.

  10. Towards the coupling of single photons from dye molecules to a photonic waveguide

    NASA Astrophysics Data System (ADS)

    Polisseni, Claudio; Kho, Kiang Wei; Major, Kyle; Grandi, Samuele; Boisser, Sebastien; Hwang, Jaesuk; Clark, Alex; Hinds, Edward

    Single photons are very attractive for quantum information processing given their long coherence time and their ability to carry information in many degrees of freedom. A current challenge is the efficient generation of single photons in a photonic chip in order to scale up the complexity of quantum operations. We have proposed that a dibenzoterrylene (DBT) molecule inside an anthracene (AC) crystal could couple lifetime-limited indistinguishable single photons into a photonic waveguide if deposited in its vicinity. In this talk I describe the recent progress towards the realization of this proposal. A new method has been developed for evaporating AC and DBT to produce crystals that are wide and thin. The crystals are typically several microns across and have remarkably uniform thickness, which we control between 20 and 150 nm. The crystal growth is carried out in a glove bag in order to exclude oxygen, which improves the photostability of the DBT molecules by orders of magnitude. We image the fluorescence of single DBT molecules using confocal microscopy and analyse the polarization of this light to determine the alignment of the molecules. I will report on our efforts to control the alignement of the molecules by aligning the host matrix with the substrate.

  11. Tunable Raman photons in singly charged p -doped quantum dots

    NASA Astrophysics Data System (ADS)

    Carreño, F.; Antón, M. A.

    2016-03-01

    The obtention of spontaneous Raman photons is analyzed in singly charged p -doped quantum dots in the absence of an external magnetic field. The use of a far detuned single driving laser allows one to obtain a Raman photon line which exhibits a subnatural linewidth, and whose center can be tuned by changing the detuning and/or the Rabi frequency of the driving field. The Raman photons are produced along the undriven transition and they arise from a weak interaction of the trion states with the nuclear spins. The operating point for the gate voltage of the heterostructure can also be used to modify the linewidth and the peak value of the fluorescent signal.

  12. Operating quantum waveguide circuits with superconducting single-photon detectors

    NASA Astrophysics Data System (ADS)

    Natarajan, C. M.; Peruzzo, A.; Miki, S.; Sasaki, M.; Wang, Z.; Baek, B.; Nam, S.; Hadfield, R. H.; O'Brien, J. L.

    2010-05-01

    Advanced quantum information science and technology (QIST) applications place exacting demands on optical components. Quantum waveguide circuits offer a route to scalable QIST on a chip. Superconducting single-photon detectors (SSPDs) provide infrared single-photon sensitivity combined with low dark counts and picosecond timing resolution. In this study, we bring these two technologies together. Using SSPDs we observe a two-photon interference visibility of 92.3±1.0% in a silica-on-silicon waveguide directional coupler at λ =804 nm—higher than that measured with silicon detectors (89.9±0.3%). We further operated controlled-NOT gate and quantum metrology circuits with SSPDs. These demonstrations present a clear path to telecom-wavelength quantum waveguide circuits.

  13. Modelling superconducting nanowire single photon detectors in a waveguide cavity.

    PubMed

    Tyler, Nicola A; Barreto, Jorge; Villarreal-Garcia, Gerardo E; Bonneau, Damien; Sahin, Döndü; O'Brien, Jeremy L; Thompson, Mark G

    2016-04-18

    In this work we report on a single photon detector system which offers near-unity detection efficiency using waveguide-coupled superconducting nanowires with lengths on the order of 1 μm. This is achieved by embedding the nanowires in a racetrack resonator where the interaction time with the photons trapped in the cavity is increased, thereby allowing for shorter nanowires. We expect this to lead to a higher fabrication yield as the amount of inhomogeneities decreases for shorter nanowires. Our simulations show a system with a 1 μm long superconducting nanowire single photon detector (SNSPD) operating at near-unity detection efficiency using design parameters that can be realistically achieved with conventional fabrication processes. The resonant cavity introduces spectral selectivity to the otherwise broad-band SNSPDs and the cavity induced timing jitter is shown to be insignificant for SNSPDs longer than 1 μm. PMID:27137314

  14. Advanced active quenching circuits for single-photon avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Stipčević, M.; Christensen, B. G.; Kwiat, P. G.; Gauthier, D. J.

    2016-05-01

    Commercial photon-counting modules, often based on actively quenched solid-state avalanche photodiode sensors, are used in wide variety of applications. Manufacturers characterize their detectors by specifying a small set of parameters, such as detection efficiency, dead time, dark counts rate, afterpulsing probability and single photon arrival time resolution (jitter), however they usually do not specify the conditions under which these parameters are constant or present a sufficient description. In this work, we present an in-depth analysis of the active quenching process and identify intrinsic limitations and engineering challenges. Based on that, we investigate the range of validity of the typical parameters used by two commercial detectors. We identify an additional set of imperfections that must be specified in order to sufficiently characterize the behavior of single-photon counting detectors in realistic applications. The additional imperfections include rate-dependence of the dead time, jitter, detection delay shift, and "twilighting." Also, the temporal distribution of afterpulsing and various artifacts of the electronics are important. We find that these additional non-ideal behaviors can lead to unexpected effects or strong deterioration of the system's performance. Specifically, we discuss implications of these new findings in a few applications in which single-photon detectors play a major role: the security of a quantum cryptographic protocol, the quality of single-photon-based random number generators and a few other applications. Finally, we describe an example of an optimized avalanche quenching circuit for a high-rate quantum key distribution system based on time-bin entangled photons.

  15. Single photon emission computed tomography and other selected computer topics

    SciTech Connect

    Price, R.R.; Gilday, D.L.; Croft, B.Y.

    1980-01-01

    This volume includes an overview of single photon emission computed tomography and numerous papers that describe and evaluate specific systems and techniques. Papers cover such topics as Auger cameras; seven-pinhole and slant-hole collimators; brain; cardiac; and gated blood-pool studies; and the BICLET and SPECT systems.

  16. High-speed single-photon signaling for daytime QKD

    NASA Astrophysics Data System (ADS)

    Bienfang, Joshua; Restelli, Alessandro; Clark, Charles

    2011-03-01

    The distribution of quantum-generated cryptographic key at high throughputs can be critically limited by the performance of the systems' single-photon detectors. While noise and afterpulsing are considerations for all single-photon QKD systems, high-transmission rate systems also have critical detector timing-resolution and recovery time requirements. We present experimental results exploiting the high timing resolution and count-rate stability of modified single-photon avalanche diodes (SPADs) in our GHz QKD system operating over a 1.5 km free-space link that demonstrate the ability to apply extremely short temporal gates, enabling daytime free-space QKD with a 4% QBER. We also discuss recent advances in gating techniques for InGaAs SPADs that are suitable for high-speed fiber-based QKD. We present afterpulse-probability measurements that demonstrate the ability to support single-photon count rates above 100 MHz with low afterpulse probability. These results will benefit the design and characterization of free-space and fiber QKD systems. A. Restelli, J.C. Bienfang A. Mink, and C.W. Clark, IEEE J. Sel. Topics in Quant. Electron 16, 1084 (2010).

  17. Single-Photon Source for Quantum Information Based on Single Dye Molecule Fluorescence in Liquid Crystal Host

    SciTech Connect

    Lukishova, S.G.; Knox, R.P.; Freivald, P.; McNamara, A.; Boyd, R.W.; Stroud, Jr., C.R.; Schmid, A.W.; Marshall, K.L.

    2006-08-18

    This paper describes a new application for liquid crystals: quantum information technology. A deterministically polarized single-photon source that efficiently produces photons exhibiting antibunching is a pivotal hardware element in absolutely secure quantum communication. Planar-aligned nematic liquid crystal hosts deterministically align the single dye molecules which produce deterministically polarized single (antibunched) photons. In addition, 1-D photonic bandgap cholesteric liquid crystals will increase single-photon source efficiency. The experiments and challenges in the observation of deterministically polarized fluorescence from single dye molecules in planar-aligned glassy nematic-liquid-crystal oligomer as well as photon antibunching in glassy cholesteric oligomer are described for the first time.

  18. Single photon detection with self-quenching multiplication

    NASA Technical Reports Server (NTRS)

    Zheng, Xinyu (Inventor); Cunningham, Thomas J. (Inventor); Pain, Bedabrata (Inventor)

    2011-01-01

    A photoelectronic device and an avalanche self-quenching process for a photoelectronic device are described. The photoelectronic device comprises a nanoscale semiconductor multiplication region and a nanoscale doped semiconductor quenching structure including a depletion region and an undepletion region. The photoelectronic device can act as a single photon detector or a single carrier multiplier. The avalanche self-quenching process allows electrical field reduction in the multiplication region by movement of the multiplication carriers, thus quenching the avalanche.

  19. Tapered fiber coupling of single photons emitted by a deterministically positioned single nitrogen vacancy center

    SciTech Connect

    Liebermeister, Lars Petersen, Fabian; Münchow, Asmus v.; Burchardt, Daniel; Hermelbracht, Juliane; Tashima, Toshiyuki; Schell, Andreas W.; Benson, Oliver; Meinhardt, Thomas; Krueger, Anke; Stiebeiner, Ariane; Rauschenbeutel, Arno; Weinfurter, Harald; Weber, Markus

    2014-01-20

    A diamond nano-crystal hosting a single nitrogen vacancy (NV) center is optically selected with a confocal scanning microscope and positioned deterministically onto the subwavelength-diameter waist of a tapered optical fiber (TOF) with the help of an atomic force microscope. Based on this nano-manipulation technique, we experimentally demonstrate the evanescent coupling of single fluorescence photons emitted by a single NV-center to the guided mode of the TOF. By comparing photon count rates of the fiber-guided and the free-space modes and with the help of numerical finite-difference time domain simulations, we determine a lower and upper bound for the coupling efficiency of (9.5 ± 0.6)% and (10.4 ± 0.7)%, respectively. Our results are a promising starting point for future integration of single photon sources into photonic quantum networks and applications in quantum information science.

  20. High-visibility nonclassical interference between intrinsically pure heralded single photons and photons from a weak coherent field

    SciTech Connect

    Jin Ruibo; Zhang Jun; Matsuda, Nobuyuki; Mitsumori, Yasuyoshi; Kosaka, Hideo; Edamatsu, Keiichi; Shimizu, Ryosuke

    2011-03-15

    We present an experiment of nonclassical interference between an intrinsically pure heralded single-photon state and a weak coherent state. Our experiment demonstrates that, without the use of bandpass filters, spectrally pure single photons can have high-visibility (89.4{+-}0.5%) interference with photons from a weak coherent field. Our scheme lays the groundwork for future experiments requiring quantum interference between photons in nonclassical states and those in coherent states.

  1. The single photon superradiance from the eigenmode analysis

    NASA Astrophysics Data System (ADS)

    Manassah, Jamal T.

    2009-11-01

    Using the eigenmode analysis of the scalar photon theory, I compute the probability of the atoms remaining excited and the probability for the atoms remaining in the initial quantum state of a system of two-level atoms cloud in a sphere initially prepared to radiate in the forward direction, i.e., the single photon superradiance problem. The convergence in the results obtained for increasingly larger radii for the sphere suggests that the asymptotic limits for these quantities are obtained for a sphere with a radius equal to six times the resonant wavelength. I predict the maximal value of the probability of secondary excited states from large spheres at 17.1%.

  2. Deterministic and storable single photons from a multilayer microsphere

    SciTech Connect

    Tuan Anh Nguyen; Ho Trung Dung

    2007-09-15

    We consider the generation of single photons on demand by pumping an emitter which is enclosed within a spherical distributed dielectric resonator, and then letting it emit spontaneously. The three-dimensional confinement in space of the electromagnetic field gives rise to deep dips and high peaks in the spectral profile of the density of states. The dips can be made use of to store the excitation energy and the peaks to narrow the time window during which a photon is emitted. The feasibility of the proposed scheme is discussed.

  3. Protocols for a quantum network based on single photons

    NASA Astrophysics Data System (ADS)

    Blum, Susanne; O'Brien, Christopher; Reich, Daniel; Lauk, Nikolai; Koch, Christiane; Fleischhauer, Michael; Morigi, Giovanna

    2015-03-01

    Two protocols for interfacing single optical photons with individual qubits are theoretically discussed. The first is a protocol which allows one to interface a single optical photon with a superconducting qubit. It makes use of a a spin ensemble, where the individual emitters possess both an optical and a magnetic dipole transition. Reversible frequency conversion is realized by combining optical photon storage, for instance by means of EIT, with the controlled switching on and off the coupling of the magnetic dipole transition with a microwave cavity, which in turn couples to a superconducting qubit. We test various strategies and compare their efficiencies in terms of robustness and transfer time. The second protocol aims at achieving perfect absorption of a photon by a single trapped atom, or solid-state emitter, by means of optimal control theory. We make use of the Krotov algorithm for the purpose of identifying pulses driving the atom, that maximize the efficiency and fidelity of absorption in the setup of. These protocols contribute to the development of a toolbox for quantum networks using hybrid platforms.

  4. Single-quantum dot imaging with a photon counting camera

    PubMed Central

    Michalet, X.; Colyer, R. A.; Antelman, J.; Siegmund, O.H.W.; Tremsin, A.; Vallerga, J.V.; Weiss, S.

    2010-01-01

    The expanding spectrum of applications of single-molecule fluorescence imaging ranges from fundamental in vitro studies of biomolecular activity to tracking of receptors in live cells. The success of these assays has relied on progresses in organic and non-organic fluorescent probe developments as well as improvements in the sensitivity of light detectors. We describe a new type of detector developed with the specific goal of ultra-sensitive single-molecule imaging. It is a wide-field, photon-counting detector providing high temporal and high spatial resolution information for each incoming photon. It can be used as a standard low-light level camera, but also allows access to a lot more information, such as fluorescence lifetime and spatio-temporal correlations. We illustrate the single-molecule imaging performance of our current prototype using quantum dots and discuss on-going and future developments of this detector. PMID:19689323

  5. Superior Optical Properties of Perovskite Nanocrystals as Single Photon Emitters.

    PubMed

    Hu, Fengrui; Zhang, Huichao; Sun, Chun; Yin, Chunyang; Lv, Bihu; Zhang, Chunfeng; Yu, William W; Wang, Xiaoyong; Zhang, Yu; Xiao, Min

    2015-12-22

    The power conversion efficiency of photovoltaic devices based on semiconductor perovskites has reached ∼20% after just several years of research efforts. With concomitant discoveries of other promising applications in lasers, light-emitting diodes, and photodetectors, it is natural to anticipate what further excitement these exotic perovskites could bring about. Here we report on the observation of single photon emission from single CsPbBr3 perovskite nanocrystals (NCs) synthesized from a facile colloidal approach. Compared with traditional metal-chalcogenide NCs, these CsPbBr3 NCs exhibit nearly 2 orders of magnitude increase in their absorption cross sections at similar emission colors. Moreover, the radiative lifetime of CsPbBr3 NCs is greatly shortened at both room and cryogenic temperatures to favor an extremely fast output of single photons. The above superior optical properties have paved the way toward quantum-light applications of perovskite NCs in various quantum information processing schemes. PMID:26522082

  6. Single-photon imaging camera development for night vision

    NASA Astrophysics Data System (ADS)

    Vasile, Stefan; Cheng, Jing; Lipson, Jerold; Liu, Jifeng; Michel, Jurgen

    2010-04-01

    Single-photon imaging in infrared will add a new valuable tool to night imaging cameras. Despite years of development, high-sensitivity SWIR cameras are still expensive and not ready for large-volume production. Germanium (Ge) is a promising semiconductor to convert SWIR radiation and it has seen extensive development in conjunction with highspeed optical communications. We are demonstrating a new low-light level infrared array technology based on the single-photon sensitive Geiger avalanche PhotoDiode (Si-GPD) array technology developed at aPeak and low-dislocation Germanium processing developed at MIT. The core of the imaging camera is a Ge:Si photon-counting GPD pixel with CMOS readout. The primary technology objective is to demonstrate through prototyping and semiconductor process development the technical feasibility of single-photon detection cameras sensitive in the SWIR and set the performance specifications. We report on prototype Ge:Si structures compatible with the GPD operation and technology. We demonstrate >80% quantum efficiency at 1310nm and 45%-60% quantum efficiency at 1550nm. Dark current measurements indicate that single-photon sensitivity (2.6x10-18W/pixel) is achievable by cooling the detector at cryogenic temperatures down to 53K. A digital developed to provide adjustable dynamic range and frame rate is reported. Because the GPD detectors have intrinsic excellent gating and ranging capability, the pixel architecture is developed to enable the dual mode operation - passive illumination two-dimensional imaging (night vision) and active illumination three-dimensional imaging.

  7. Modeling of kinetic processes in thermoelectric single photon detectors

    NASA Astrophysics Data System (ADS)

    Kuzanyan, Armen; Nikoghosyan, Vahan; Kuzanyan, Astghik

    2015-05-01

    The results of computer modeling of the thermoelectric single-photon detector are presented. We observe the processes of heat distribution after absorption of a photon of 0.1-1 keV energy in different parts of the absorber for different geometries of absorbers and thermoelectric sensors. The calculations were carried out by the matrix method for differential equations using parameters for the tungsten absorber and thermoelectric sensor made of (La, Ce)B6. The results of calculations show that it is realistic to detect photons about 0.1-1 keV and determine their energy with accuracy of not less than 1%. High count rates up to 200 GHz can be achieved.

  8. Modal Coupling of Single Photon Emitters Within Nanofiber Waveguides.

    PubMed

    Gaio, Michele; Moffa, Maria; Castro-Lopez, Marta; Pisignano, Dario; Camposeo, Andrea; Sapienza, Riccardo

    2016-06-28

    Nanoscale generation of individual photons in confined geometries is an exciting research field aiming at exploiting localized electromagnetic fields for light manipulation. One of the outstanding challenges of photonic systems combining emitters with nanostructured media is the selective channelling of photons emitted by embedded sources into specific optical modes and their transport at distant locations in integrated systems. Here, we show that soft-matter nanofibers, electrospun with embedded emitters, combine subwavelength field localization and large broadband near-field coupling with low propagation losses. By momentum spectroscopy, we quantify the modal coupling efficiency identifying the regime of single-mode coupling. These nanofibers do not rely on resonant interactions, making them ideal for room-temperature operation, and offer a scalable platform for future quantum information technology. PMID:27203403

  9. Single photon energy dispersive x-ray diffraction

    SciTech Connect

    Higginbotham, Andrew; Patel, Shamim; Ciricosta, Orlando; Suggit, Matthew J.; Wark, Justin S.; Hawreliak, James A.; Collins, Gilbert W.; Coppari, Federica; Eggert, Jon H.; Tang, Henry

    2014-03-15

    With the pressure range accessible to laser driven compression experiments on solid material rising rapidly, new challenges in the diagnosis of samples in harsh laser environments are emerging. When driving to TPa pressures (conditions highly relevant to planetary interiors), traditional x-ray diffraction techniques are plagued by increased sources of background and noise, as well as a potential reduction in signal. In this paper we present a new diffraction diagnostic designed to record x-ray diffraction in low signal-to-noise environments. By utilising single photon counting techniques we demonstrate the ability to record diffraction patterns on nanosecond timescales, and subsequently separate, photon-by-photon, signal from background. In doing this, we mitigate many of the issues surrounding the use of high intensity lasers to drive samples to extremes of pressure, allowing for structural information to be obtained in a regime which is currently largely unexplored.

  10. Modal Coupling of Single Photon Emitters Within Nanofiber Waveguides

    PubMed Central

    2016-01-01

    Nanoscale generation of individual photons in confined geometries is an exciting research field aiming at exploiting localized electromagnetic fields for light manipulation. One of the outstanding challenges of photonic systems combining emitters with nanostructured media is the selective channelling of photons emitted by embedded sources into specific optical modes and their transport at distant locations in integrated systems. Here, we show that soft-matter nanofibers, electrospun with embedded emitters, combine subwavelength field localization and large broadband near-field coupling with low propagation losses. By momentum spectroscopy, we quantify the modal coupling efficiency identifying the regime of single-mode coupling. These nanofibers do not rely on resonant interactions, making them ideal for room-temperature operation, and offer a scalable platform for future quantum information technology. PMID:27203403

  11. Single-photon-interference communication equivalent to Bell-state-basis cryptographic quantum communication

    NASA Astrophysics Data System (ADS)

    Shimizu, Kaoru; Imoto, Nobuyuki

    2000-11-01

    We propose a single-photon interferometer which provides cryptographic quantum communication equivalent to that obtained using a pair of polarization entangled photon twins as a carrier [Phys. Rev. A 60, 157 (1999)]. Instead of manipulating and measuring the internal states of entangled photon twins, cryptographic quantum communication is possible by manipulating a single photon in an extended interferometer. The use of the single-photon interferometer offers significant experimental advantages compared to our previous approach.

  12. Photonic Quantum Logic with Narrowband Light from Single Atoms

    NASA Astrophysics Data System (ADS)

    Rubenok, Allison; Holleczek, Annemarie; Barter, Oliver; Dilley, Jerome; Nisbet-Jones, Peter B. R.; Langfahl-Klabes, Gunnar; Kuhn, Axel; Sparrow, Chris; Marshall, Graham D.; O'Brien, Jeremy L.; Poulios, Konstantinos; Matthews, Jonathan C. F.

    Atom-cavity sources of narrowband photons are a promising candidate for the future development of quantum technologies. Likewise, integrated photonic circuits have established themselves as a fore-running contender in quantum computing, security, and communication. Here we report on recent achievements to interface these two technologies: Atom-cavity sources coupled to integrated photonic circuits. Using narrow linewidth photons emitted from a single 87 Rb atom strongly coupled to a high-finesse cavity we demonstrate the successful operation of an integrated control-not gate. Furthermore, we are able to verify the generation of post-selected entanglement upon successful operation of the gate. We are able to see non-classical correlations in detection events that are up to three orders of magnitude farther apart than the time needed for light to travel across the chip. Our hybrid approach will facilitate the future development of technologies that benefit from the advantages of both integrated quantum circuits and atom-cavity photon sources. Now at: National Physics Laboratory.

  13. Deterministic Integration of Single Photon Sources in Silicon Based Photonic Circuits.

    PubMed

    Zadeh, Iman Esmaeil; Elshaari, Ali W; Jöns, Klaus D; Fognini, Andreas; Dalacu, Dan; Poole, Philip J; Reimer, Michael E; Zwiller, Val

    2016-04-13

    A major step toward fully integrated quantum optics is the deterministic incorporation of high quality single photon sources in on-chip optical circuits. We show a novel hybrid approach in which preselected III-V single quantum dots in nanowires are transferred and integrated in silicon based photonic circuits. The quantum emitters maintain their high optical quality after integration as verified by measuring a low multiphoton probability of 0.07 ± 0.07 and emission line width as narrow as 3.45 ± 0.48 GHz. Our approach allows for optimum alignment of the quantum dot light emission to the fundamental waveguide mode resulting in very high coupling efficiencies. We estimate a coupling efficiency of 24.3 ± 1.7% from the studied single-photon source to the photonic channel and further show by finite-difference time-domain simulations that for an optimized choice of material and design the efficiency can exceed 90%. PMID:26954298

  14. Quantum-state purity of heralded single photons produced from frequency-anticorrelated biphotons

    NASA Astrophysics Data System (ADS)

    Du, Shengwang

    2015-10-01

    We analyze the quantum-state purity of heralded single photons produced from frequency-anticorrelated biphotons. We find that the quantum-state purity in the time-frequency domain depends strongly on the response time uncertainty of the trigger-photon detector that heralds the generation of its paired photon. If the trigger response time is much shorter than the two-photon coherence time, the time-frequency quantum-state purity of heralded single photons approaches unity and the heralded single photon is in a nearly pure state. If the trigger response time is much longer than the two-photon coherence time, the heralded photon is then projected onto a mixed state. Making use of the time-frequency entanglement, heralded single photons with a well-defined temporal wave function or a frequency superposition state can be produced and engineered. This time-frequency entanglement allows for shaping heralded single photons through nonlocal spectral modulation.

  15. Broadband single-photon-level memory in a hollow-core photonic crystal fibre

    NASA Astrophysics Data System (ADS)

    Sprague, M. R.; Michelberger, P. S.; Champion, T. F. M.; England, D. G.; Nunn, J.; Jin, X.-M.; Kolthammer, W. S.; Abdolvand, A.; Russell, P. St. J.; Walmsley, I. A.

    2014-04-01

    Storing information encoded in light is critical for realizing optical buffers for all-optical signal processing and quantum memories for quantum information processing. These proposals require efficient interaction between atoms and a well-defined optical mode. Photonic crystal fibres can enhance light-matter interactions and have engendered a broad range of nonlinear effects; however, the storage of light has proven elusive. Here, we report the first demonstration of an optical memory in a hollow-core photonic crystal fibre. We store gigahertz-bandwidth light in the hyperfine coherence of caesium atoms at room temperature using a far-detuned Raman interaction. We demonstrate a signal-to-noise ratio of 2.6:1 at the single-photon level and a memory efficiency of 27 +/- 1%. Our results demonstrate the potential of a room-temperature fibre-integrated optical memory for implementing local nodes of quantum information networks.

  16. Quantum private query based on single-photon interference

    NASA Astrophysics Data System (ADS)

    Xu, Sheng-Wei; Sun, Ying; Lin, Song

    2016-08-01

    Quantum private query (QPQ) has become a research hotspot recently. Specially, the quantum key distribution (QKD)-based QPQ attracts lots of attention because of its practicality. Various such kind of QPQ protocols have been proposed based on different technologies of quantum communications. Single-photon interference is one of such technologies, on which the famous QKD protocol GV95 is just based. In this paper, we propose two QPQ protocols based on single-photon interference. The first one is simpler and easier to realize, and the second one is loss tolerant and flexible, and more practical than the first one. Furthermore, we analyze both the user privacy and the database privacy in the proposed protocols.

  17. Single-photon superradiance and radiation trapping by atomic shells

    NASA Astrophysics Data System (ADS)

    Svidzinsky, Anatoly A.; Li, Fu; Li, Hongyuan; Zhang, Xiwen; Ooi, C. H. Raymond; Scully, Marlan O.

    2016-04-01

    The collective nature of light emission by atomic ensembles yields fascinating effects such as superradiance and radiation trapping even at the single-photon level. Light emission is influenced by virtual transitions and the collective Lamb shift which yields peculiar features in temporal evolution of the atomic system. We study how two-dimensional atomic structures collectively emit a single photon. Namely, we consider spherical, cylindrical, and spheroidal shells with two-level atoms continuously distributed on the shell surface and find exact analytical solutions for eigenstates of such systems and their collective decay rates and frequency shifts. We identify states which undergo superradiant decay and states which are trapped and investigate how size and shape of the shell affects collective light emission. Our findings could be useful for quantum information storage and the design of optical switches.

  18. Quantum private query based on single-photon interference

    NASA Astrophysics Data System (ADS)

    Xu, Sheng-Wei; Sun, Ying; Lin, Song

    2016-05-01

    Quantum private query (QPQ) has become a research hotspot recently. Specially, the quantum key distribution (QKD)-based QPQ attracts lots of attention because of its practicality. Various such kind of QPQ protocols have been proposed based on different technologies of quantum communications. Single-photon interference is one of such technologies, on which the famous QKD protocol GV95 is just based. In this paper, we propose two QPQ protocols based on single-photon interference. The first one is simpler and easier to realize, and the second one is loss tolerant and flexible, and more practical than the first one. Furthermore, we analyze both the user privacy and the database privacy in the proposed protocols.

  19. Localization of Narrowband Single Photon Emitters in Nanodiamonds.

    PubMed

    Bray, Kerem; Sandstrom, Russell; Elbadawi, Christopher; Fischer, Martin; Schreck, Matthias; Shimoni, Olga; Lobo, Charlene; Toth, Milos; Aharonovich, Igor

    2016-03-23

    Diamond nanocrystals that host room temperature narrowband single photon emitters are highly sought after for applications in nanophotonics and bioimaging. However, current understanding of the origin of these emitters is extremely limited. In this work, we demonstrate that the narrowband emitters are point defects localized at extended morphological defects in individual nanodiamonds. In particular, we show that nanocrystals with defects such as twin boundaries and secondary nucleation sites exhibit narrowband emission that is absent from pristine individual nanocrystals grown under the same conditions. Critically, we prove that the narrowband emission lines vanish when extended defects are removed deterministically using highly localized electron beam induced etching. Our results enhance the current understanding of single photon emitters in diamond and are directly relevant to fabrication of novel quantum optics devices and sensors. PMID:26937848

  20. Silicon technologies for arrays of Single Photon Avalanche Diodes

    NASA Astrophysics Data System (ADS)

    Gulinatti, Angelo; Ceccarelli, Francesco; Rech, Ivan; Ghioni, Massimo

    2016-05-01

    In order to fulfill the requirements of many applications, we recently developed a new technology aimed at combining the advantages of traditional thin and thick silicon Single Photon Avalanche Diodes (SPAD). In particular we demonstrated single-pixel detectors with a remarkable improvement in the Photon Detection Efficiency in the red/nearinfrared spectrum (e.g. 40% at 800nm) while maintaining a timing jitter better than 100ps. In this paper we discuss the limitations of such Red-Enhanced (RE) technology from the point of view of the fabrication of small arrays of SPAD and we propose modifications to the structure aimed at overcoming these issues. We also report the first preliminary experimental results attained on devices fabricated adopting the improved structure.

  1. Authenticated Quantum Key Distribution with Collective Detection using Single Photons

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Xu, Bing-Jie; Duan, Ji-Tong; Liu, Bin; Su, Qi; He, Yuan-Hang; Jia, Heng-Yue

    2016-05-01

    We present two authenticated quantum key distribution (AQKD) protocols by utilizing the idea of collective (eavesdropping) detection. One is a two-party AQKD protocol, the other is a multiparty AQKD protocol with star network topology. In these protocols, the classical channels need not be assumed to be authenticated and the single photons are used as the quantum information carriers. To achieve mutual identity authentication and establish a random key in each of the proposed protocols, only one participant should be capable of preparing and measuring single photons, and the main quantum ability that the rest of the participants should have is just performing certain unitary operations. Security analysis shows that these protocols are free from various kinds of attacks, especially the impersonation attack and the man-in-the-middle (MITM) attack.

  2. Research on VCSEL of single-mode multilayer photonic crystal

    NASA Astrophysics Data System (ADS)

    Li, Wenchao; Liu, Zhengjun; Sha, Xiaopeng

    2010-10-01

    Vertical-Cavity Surface-Emitting Lasers (VCSEL) of single mode have the potential advantage in the domains of optical information network, routing interactions, optical information storage and data transmission for their excellent performance. However, operating on the single-mode model in the whole pumped area is not solved, which impacts the technologies and applications. In this paper, a new research on VCSEL of single mode multilayer photonic crystal is presented. In the structure of photonic crystal, defects in the horizontal direction are provided by the micro-cavity, while the AIR-KTP interface on the top and the KTP-DBR (Distributed Bragg Reflection) interface at the bottom of cavity provide the defects in the vertical direction, which form quantum defects of electron-hole pairs. The PC-VCSEL in the paper has excellent mode-selection characteristics, which can operate continuously at 850nm in single mode. The single-mode suppression ratio (SMSR) of 45dB is obtained in a wide dynamic range. The PC-VCSEL is expected to become a high-power single-mode light in the future.

  3. Single-photon ultrashort-lived radionuclides: symposium proceedings

    SciTech Connect

    Paras, P.; Thiessen, J.W.

    1985-01-01

    The purpose was to define the current role and state-of-the-art regarding the development, clinical applications, and usefulness of generator-produced single-photon ultrashort-lived radionuclides (SPUSLR's) and to predict their future impact on medicine. Special emphasis was placed on the generator production of iridium-191, gold-195, and krypton-81. This report contains expanded summaries of the included papers. (ACR)

  4. Nonlocality from N>2 independent single-photon emitters

    SciTech Connect

    Thiel, C.; Wiegner, R.; Zanthier, J. von; Agarwal, G. S.

    2010-09-15

    We demonstrate that intensity correlations of second order in the fluorescence light of N>2 single-photon emitters may violate locality while the visibility of the signal remains below 1/{radical}(2){approx_equal}71%. For this, we derive a homogeneous Bell-Wigner-type inequality, which can be applied to a broad class of experimental setups. We trace the violation of this inequality back to path entanglement created by the process of detection.

  5. Processing of transmission data from an uncollimated single photon source

    NASA Astrophysics Data System (ADS)

    Dikaios, N.; Dinelle, K.; Spinks, T.; Nikita, K.; Thielemans, K.

    2006-12-01

    The EXACT 3D PET scanner uses a Cs-137 single photon rotating point source for the transmission scan. As the source is un-collimated, the transmission data are contaminated by scatter. It has been suggested that segmentation of the reconstructed image can restore the quantitative information in the image. We study here if the results can be further improved by the application of a scale factor for every transaxial plane.

  6. Triggered generation of single guided photons from a single atom in a nanofiber cavity

    SciTech Connect

    Le Kien, Fam; Hakuta, K.

    2011-04-15

    We study the deterministic generation of single guided-mode photons from an atom in the vicinity of a nanofiber with two fiber-Bragg-grating (FBG) mirrors. The technique is based on a cavity-enhanced Raman scattering process involving an adiabatic passage. We take into account the scattering of the pump field from the fiber, the multilevel structure of the atom, and the surface-induced van der Waals potential in describing the photon generation process. We find that, due to the confinement of the cavity field in the transverse plane of the fiber and in the space between the FBG mirrors, the probability of the generation of a single guided-mode photon can be close to unity even when the finesse of the nanofiber cavity is moderate. We show the possibilities of saturation and power broadening in the behavior of the number of photons emitted into the nanofiber.

  7. Single-photon imaging in complementary metal oxide semiconductor processes

    PubMed Central

    Charbon, E.

    2014-01-01

    This paper describes the basics of single-photon counting in complementary metal oxide semiconductors, through single-photon avalanche diodes (SPADs), and the making of miniaturized pixels with photon-counting capability based on SPADs. Some applications, which may take advantage of SPAD image sensors, are outlined, such as fluorescence-based microscopy, three-dimensional time-of-flight imaging and biomedical imaging, to name just a few. The paper focuses on architectures that are best suited to those applications and the trade-offs they generate. In this context, architectures are described that efficiently collect the output of single pixels when designed in large arrays. Off-chip readout circuit requirements are described for a variety of applications in physics, medicine and the life sciences. Owing to the dynamic nature of SPADs, designs featuring a large number of SPADs require careful analysis of the target application for an optimal use of silicon real estate and of limited readout bandwidth. The paper also describes the main trade-offs involved in architecting such chips and the solutions adopted with focus on scalability and miniaturization. PMID:24567470

  8. Single-photon imaging in complementary metal oxide semiconductor processes.

    PubMed

    Charbon, E

    2014-03-28

    This paper describes the basics of single-photon counting in complementary metal oxide semiconductors, through single-photon avalanche diodes (SPADs), and the making of miniaturized pixels with photon-counting capability based on SPADs. Some applications, which may take advantage of SPAD image sensors, are outlined, such as fluorescence-based microscopy, three-dimensional time-of-flight imaging and biomedical imaging, to name just a few. The paper focuses on architectures that are best suited to those applications and the trade-offs they generate. In this context, architectures are described that efficiently collect the output of single pixels when designed in large arrays. Off-chip readout circuit requirements are described for a variety of applications in physics, medicine and the life sciences. Owing to the dynamic nature of SPADs, designs featuring a large number of SPADs require careful analysis of the target application for an optimal use of silicon real estate and of limited readout bandwidth. The paper also describes the main trade-offs involved in architecting such chips and the solutions adopted with focus on scalability and miniaturization. PMID:24567470

  9. High-fidelity frequency down-conversion of visible entangled photon pairs with superconducting single-photon detectors

    SciTech Connect

    Ikuta, Rikizo; Kato, Hiroshi; Kusaka, Yoshiaki; Yamamoto, Takashi; Imoto, Nobuyuki; Miki, Shigehito; Yamashita, Taro; Terai, Hirotaka; Wang, Zhen; Fujiwara, Mikio; Sasaki, Masahide; Koashi, Masato

    2014-12-04

    We experimentally demonstrate a high-fidelity visible-to-telecommunicationwavelength conversion of a photon by using a solid-state-based difference frequency generation. In the experiment, one half of a pico-second visible entangled photon pair at 780 nm is converted to a 1522-nm photon. Using superconducting single-photon detectors with low dark count rates and small timing jitters, we observed a fidelity of 0.93±0.04 after the wavelength conversion.

  10. An all-silicon single-photon source by unconventional photon blockade

    PubMed Central

    Flayac, Hugo; Gerace, Dario; Savona, Vincenzo

    2015-01-01

    The lack of suitable quantum emitters in silicon and silicon-based materials has prevented the realization of room temperature, compact, stable, and integrated sources of single photons in a scalable on-chip architecture, so far. Current approaches rely on exploiting the enhanced optical nonlinearity of silicon through light confinement or slow-light propagation, and are based on parametric processes that typically require substantial input energy and spatial footprint to reach a reasonable output yield. Here we propose an alternative all-silicon device that employs a different paradigm, namely the interplay between quantum interference and the third-order intrinsic nonlinearity in a system of two coupled optical cavities. This unconventional photon blockade allows to produce antibunched radiation at extremely low input powers. We demonstrate a reliable protocol to operate this mechanism under pulsed optical excitation, as required for device applications, thus implementing a true single-photon source. We finally propose a state-of-art implementation in a standard silicon-based photonic crystal integrated circuit that outperforms existing parametric devices either in input power or footprint area. PMID:26061665

  11. An all-silicon single-photon source by unconventional photon blockade.

    PubMed

    Flayac, Hugo; Gerace, Dario; Savona, Vincenzo

    2015-01-01

    The lack of suitable quantum emitters in silicon and silicon-based materials has prevented the realization of room temperature, compact, stable, and integrated sources of single photons in a scalable on-chip architecture, so far. Current approaches rely on exploiting the enhanced optical nonlinearity of silicon through light confinement or slow-light propagation, and are based on parametric processes that typically require substantial input energy and spatial footprint to reach a reasonable output yield. Here we propose an alternative all-silicon device that employs a different paradigm, namely the interplay between quantum interference and the third-order intrinsic nonlinearity in a system of two coupled optical cavities. This unconventional photon blockade allows to produce antibunched radiation at extremely low input powers. We demonstrate a reliable protocol to operate this mechanism under pulsed optical excitation, as required for device applications, thus implementing a true single-photon source. We finally propose a state-of-art implementation in a standard silicon-based photonic crystal integrated circuit that outperforms existing parametric devices either in input power or footprint area. PMID:26061665

  12. Interferometric methods to measure orbital and spin, or the total angular momentum of a single photon.

    PubMed

    Leach, Jonathan; Courtial, Johannes; Skeldon, Kenneth; Barnett, Stephen M; Franke-Arnold, Sonja; Padgett, Miles J

    2004-01-01

    We propose interferometric methods capable of measuring either the total angular momentum, or simultaneously measuring the spin and orbital angular momentum of single photons. This development enables the measurement of any angular momentum eigenstate of a single photon. The work allows the investigation of single-photon two-qubit entangled states and has implications for high density information transfer. PMID:14753990

  13. Signal acquisition via polarization modulation in single photon sources.

    PubMed

    McDonnell, Mark D; Flitney, Adrian P

    2009-12-01

    A simple model system is introduced for demonstrating how a single photon source might be used to transduce classical analog information. The theoretical scheme results in measurements of analog source samples that are (i) quantized in the sense of analog-to-digital conversion and (ii) corrupted by random noise that is solely due to the quantum uncertainty in detecting the polarization state of each photon. This noise is unavoidable if more than 1 bit per sample is to be transmitted and we show how it may be exploited in a manner inspired by suprathreshold stochastic resonance. The system is analyzed information theoretically, as it can be modeled as a noisy optical communication channel, although unlike classical Poisson channels, the detector's photon statistics are binomial. Previous results on binomial channels are adapted to demonstrate numerically that the classical information capacity, and thus the accuracy of the transduction, increases logarithmically with the square root of the number of photons, N. Although the capacity is shown to be reduced when an additional detector nonideality is present, the logarithmic increase with N remains. PMID:20365102

  14. Signal acquisition via polarization modulation in single photon sources

    NASA Astrophysics Data System (ADS)

    McDonnell, Mark D.; Flitney, Adrian P.

    2009-12-01

    A simple model system is introduced for demonstrating how a single photon source might be used to transduce classical analog information. The theoretical scheme results in measurements of analog source samples that are (i) quantized in the sense of analog-to-digital conversion and (ii) corrupted by random noise that is solely due to the quantum uncertainty in detecting the polarization state of each photon. This noise is unavoidable if more than 1 bit per sample is to be transmitted and we show how it may be exploited in a manner inspired by suprathreshold stochastic resonance. The system is analyzed information theoretically, as it can be modeled as a noisy optical communication channel, although unlike classical Poisson channels, the detector’s photon statistics are binomial. Previous results on binomial channels are adapted to demonstrate numerically that the classical information capacity, and thus the accuracy of the transduction, increases logarithmically with the square root of the number of photons, N . Although the capacity is shown to be reduced when an additional detector nonideality is present, the logarithmic increase with N remains.

  15. Underwater optical communications with a single photon-counting system

    NASA Astrophysics Data System (ADS)

    Hiskett, Philip A.; Lamb, Robert A.

    2014-05-01

    This paper discusses the system engineering challenges involved with the transmission of optically encoded data through water. The scenarios of data transmission from an airborne platform to a submerged platform and data transmission from a submerged platform to another submerged platform will be discussed. A photon-counting experimental system was constructed to investigate the transmission of optical data through a 1m long tank of water. This test system incorporated a laser diode operating at a wavelength of 450nm and an optical receiver containing a shallow junction, silicon single photon avalanche diode. The optical data was transmitted through the tank containing ~100 litres of water at transmission rates equivalent to 40Mb/s. The attenuation of the optical path was increased by increasing the level of scattering of the photons using Maalox. The effects on the temporal distribution of photons in the optical pulse from adding Maalox are also discussed. The synchronisation of the transmitter and receiver clocks was investigated using reference headers appended to the encoded message signal which the receiver used to correct for timing drift. The performance of this experimental system and experimental results are discussed.

  16. Single photon emitters in exfoliated WSe2 structures.

    PubMed

    Koperski, M; Nogajewski, K; Arora, A; Cherkez, V; Mallet, P; Veuillen, J-Y; Marcus, J; Kossacki, P; Potemski, M

    2015-06-01

    Crystal structure imperfections in solids often act as efficient carrier trapping centres, which, when suitably isolated, act as sources of single photon emission. The best known examples of such attractive imperfections are well-width or composition fluctuations in semiconductor heterostructures (resulting in the formation of quantum dots) and coloured centres in wide-bandgap materials such as diamond. In the recently investigated thin films of layered compounds, the crystal imperfections may logically be expected to appear at the edges of commonly investigated few-layer flakes of these materials exfoliated on alien substrates. Here, we report comprehensive optical micro-spectroscopy studies of thin layers of tungsten diselenide (WSe2), a representative semiconducting dichalcogenide with a bandgap in the visible spectral range. At the edges of WSe2 flakes (transferred onto Si/SiO2 substrates) we discover centres that, at low temperatures, give rise to sharp emission lines (100 μeV linewidth). These narrow emission lines reveal the effect of photon antibunching, the unambiguous attribute of single photon emitters. The optical response of these emitters is inherently linked to the two-dimensional properties of the WSe2 monolayer, as they both give rise to luminescence in the same energy range, have nearly identical excitation spectra and have very similar, characteristically large Zeeman effects. With advances in the structural control of edge imperfections, thin films of WSe2 may provide added functionalities that are relevant for the domain of quantum optoelectronics. PMID:25938573

  17. Single photon emitters in exfoliated WSe2 structures

    NASA Astrophysics Data System (ADS)

    Koperski, M.; Nogajewski, K.; Arora, A.; Cherkez, V.; Mallet, P.; Veuillen, J.-Y.; Marcus, J.; Kossacki, P.; Potemski, M.

    2015-06-01

    Crystal structure imperfections in solids often act as efficient carrier trapping centres, which, when suitably isolated, act as sources of single photon emission. The best known examples of such attractive imperfections are well-width or composition fluctuations in semiconductor heterostructures (resulting in the formation of quantum dots) and coloured centres in wide-bandgap materials such as diamond. In the recently investigated thin films of layered compounds, the crystal imperfections may logically be expected to appear at the edges of commonly investigated few-layer flakes of these materials exfoliated on alien substrates. Here, we report comprehensive optical micro-spectroscopy studies of thin layers of tungsten diselenide (WSe2), a representative semiconducting dichalcogenide with a bandgap in the visible spectral range. At the edges of WSe2 flakes (transferred onto Si/SiO2 substrates) we discover centres that, at low temperatures, give rise to sharp emission lines (100 μeV linewidth). These narrow emission lines reveal the effect of photon antibunching, the unambiguous attribute of single photon emitters. The optical response of these emitters is inherently linked to the two-dimensional properties of the WSe2 monolayer, as they both give rise to luminescence in the same energy range, have nearly identical excitation spectra and have very similar, characteristically large Zeeman effects. With advances in the structural control of edge imperfections, thin films of WSe2 may provide added functionalities that are relevant for the domain of quantum optoelectronics.

  18. Single photon laser altimeter simulator and statistical signal processing

    NASA Astrophysics Data System (ADS)

    Vacek, Michael; Prochazka, Ivan

    2013-05-01

    Spaceborne altimeters are common instruments onboard the deep space rendezvous spacecrafts. They provide range and topographic measurements critical in spacecraft navigation. Simultaneously, the receiver part may be utilized for Earth-to-satellite link, one way time transfer, and precise optical radiometry. The main advantage of single photon counting approach is the ability of processing signals with very low signal-to-noise ratio eliminating the need of large telescopes and high power laser source. Extremely small, rugged and compact microchip lasers can be employed. The major limiting factor, on the other hand, is the acquisition time needed to gather sufficient volume of data in repetitive measurements in order to process and evaluate the data appropriately. Statistical signal processing is adopted to detect signals with average strength much lower than one photon per measurement. A comprehensive simulator design and range signal processing algorithm are presented to identify a mission specific altimeter configuration. Typical mission scenarios (celestial body surface landing and topographical mapping) are simulated and evaluated. The high interest and promising single photon altimeter applications are low-orbit (˜10 km) and low-radial velocity (several m/s) topographical mapping (asteroids, Phobos and Deimos) and landing altimetry (˜10 km) where range evaluation repetition rates of ˜100 Hz and 0.1 m precision may be achieved. Moon landing and asteroid Itokawa topographical mapping scenario simulations are discussed in more detail.

  19. Nonsymmorphic topological photonic crystal with a single surface Dirac cone

    NASA Astrophysics Data System (ADS)

    Lu, Ling; Fang, Chen; Fu, Liang; Johnson, Steven; Joannopoulos, John; Soljacic, Marin; MIT Collaboration

    We predict a realization of the nonsymmorphic topological crystalline phase: a three-dimensional (3D) photonic crystal with a single surface Dirac cone. A single Dirac cone on the surface is the hallmark of the 3D topological insulators, where the double degeneracy at the Dirac point is protected by time-reversal symmetry and the spin-splitting away from the point is provided by the spin-orbital coupling. In our 3D topological photonic crystal, the degeneracy at the Dirac point is protected by a nonsymmorphic glide reflection and the linear splitting away from it is enabled by breaking time-reversal symmetry. Such a gapless surface state is fully robust against random disorder of any type. This bosonic topological band structure is achieved by applying alternating magnetization to gap out the 3D ''generalized Dirac points'' discovered in the bulk of our crystal. The Z2 bulk invariant is characterized through the evolution of Wannier centers. Our proposal-readily realizable using ferrimagnetic materials at microwave frequencies-can also be regarded as the photonic analog of topological crystalline insulators, providing the first 3D bosonic symmetry-protected topological system.

  20. In situ tuning the single photon emission from single quantum dots through hydrostatic pressure

    SciTech Connect

    Wu, Xuefei; Dou, Xiuming; Ding, Kun; Zhou, Pengyu; Ni, Haiqiao; Niu, Zhichuan; Jiang, Desheng; Sun, Baoquan

    2013-12-16

    We demonstrate that exciton emission wavelength in InAs/GaAs quantum dots (QDs) can be shifted up to 160 nm using hydrostatic pressure (0.4–4 GPa) in situ in an optical cryostat through an improved diamond anvil cell driven by piezoelectric actuator. It is confirmed that the high pressure does not destroy the photon anti-bunching properties of single QD emitter. Exciton emission intensity is not obviously weakened under the pressure range of 0–4 GPa. Such a tunable QD single photon emitter enables a flexibly tuned source for quantum optical experiments.

  1. A single probe for imaging photons, electrons and physical forces

    NASA Astrophysics Data System (ADS)

    Pilet, Nicolas; Lisunova, Yuliya; Lamattina, Fabio; Stevenson, Stephanie E.; Pigozzi, Giancarlo; Paruch, Patrycja; Fink, Rainer H.; Hug, Hans J.; Quitmann, Christoph; Raabe, Joerg

    2016-06-01

    The combination of complementary measurement techniques has become a frequent approach to improve scientific knowledge. Pairing of the high lateral resolution scanning force microscopy (SFM) with the spectroscopic information accessible through scanning transmission soft x-ray microscopy (STXM) permits assessing physical and chemical material properties with high spatial resolution. We present progress from the NanoXAS instrument towards using an SFM probe as an x-ray detector for STXM measurements. Just by the variation of one parameter, the SFM probe can be utilised to detect either sample photo-emitted electrons or transmitted photons. This allows the use of a single probe to detect electrons, photons and physical forces of interest. We also show recent progress and demonstrate the current limitations of using a high aspect ratio coaxial SFM probe to detect photo-emitted electrons with very high lateral resolution. Novel probe designs are proposed to further progress in using an SFM probe as a STXM detector.

  2. A single probe for imaging photons, electrons and physical forces.

    PubMed

    Pilet, Nicolas; Lisunova, Yuliya; Lamattina, Fabio; Stevenson, Stephanie E; Pigozzi, Giancarlo; Paruch, Patrycja; Fink, Rainer H; Hug, Hans J; Quitmann, Christoph; Raabe, Joerg

    2016-06-10

    The combination of complementary measurement techniques has become a frequent approach to improve scientific knowledge. Pairing of the high lateral resolution scanning force microscopy (SFM) with the spectroscopic information accessible through scanning transmission soft x-ray microscopy (STXM) permits assessing physical and chemical material properties with high spatial resolution. We present progress from the NanoXAS instrument towards using an SFM probe as an x-ray detector for STXM measurements. Just by the variation of one parameter, the SFM probe can be utilised to detect either sample photo-emitted electrons or transmitted photons. This allows the use of a single probe to detect electrons, photons and physical forces of interest. We also show recent progress and demonstrate the current limitations of using a high aspect ratio coaxial SFM probe to detect photo-emitted electrons with very high lateral resolution. Novel probe designs are proposed to further progress in using an SFM probe as a STXM detector. PMID:27146329

  3. On-demand single-photon state generation via nonlinear absorption

    SciTech Connect

    Hong Tao; Jack, Michael W.; Yamashita, Makoto

    2004-07-01

    We propose a method for producing on-demand single-photon states based on collision-induced exchanges of photons and unbalanced linear absorption between two single-mode light fields. These two effects result in an effective nonlinear absorption of photons in one of the modes, which can lead to single-photon states. A quantum nonlinear attenuator based on such a mechanism can absorb photons in a normal input light pulse and terminate the absorption at a single-photon state. Because the output light pulses containing single photons preserve the properties of the input pulses, we expect this method to be a means for building a highly controllable single-photon source.

  4. Single photon imaging and timing array sensor apparatus and method

    DOEpatents

    Smith, R. Clayton

    2003-06-24

    An apparatus and method are disclosed for generating a three-dimension image of an object or target. The apparatus is comprised of a photon source for emitting a photon at a target. The emitted photons are received by a photon receiver for receiving the photon when reflected from the target. The photon receiver determines a reflection time of the photon and further determines an arrival position of the photon on the photon receiver. An analyzer is communicatively coupled to the photon receiver, wherein the analyzer generates a three-dimensional image of the object based upon the reflection time and the arrival position.

  5. Single-photon non-linear optics with a quantum dot in a waveguide.

    PubMed

    Javadi, A; Söllner, I; Arcari, M; Hansen, S Lindskov; Midolo, L; Mahmoodian, S; Kiršanskė, G; Pregnolato, T; Lee, E H; Song, J D; Stobbe, S; Lodahl, P

    2015-01-01

    Strong non-linear interactions between photons enable logic operations for both classical and quantum-information technology. Unfortunately, non-linear interactions are usually feeble and therefore all-optical logic gates tend to be inefficient. A quantum emitter deterministically coupled to a propagating mode fundamentally changes the situation, since each photon inevitably interacts with the emitter, and highly correlated many-photon states may be created. Here we show that a single quantum dot in a photonic-crystal waveguide can be used as a giant non-linearity sensitive at the single-photon level. The non-linear response is revealed from the intensity and quantum statistics of the scattered photons, and contains contributions from an entangled photon-photon bound state. The quantum non-linearity will find immediate applications for deterministic Bell-state measurements and single-photon transistors and paves the way to scalable waveguide-based photonic quantum-computing architectures. PMID:26492951

  6. Non-blinking single-photon emitters in silica

    DOE PAGESBeta

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso de Mello

    2016-02-19

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters,more » do not blink, and have photoluminescence lifetimes of a few nanoseconds. Furthermore, photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots.« less

  7. Non-blinking single-photon emitters in silica.

    PubMed

    Rabouw, Freddy T; Cogan, Nicole M B; Berends, Anne C; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A Femius; Krauss, Todd D; Donega, Celso de Mello

    2016-01-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots. PMID:26892489

  8. Non-blinking single-photon emitters in silica

    PubMed Central

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso de Mello

    2016-01-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots. PMID:26892489

  9. Non-blinking single-photon emitters in silica

    NASA Astrophysics Data System (ADS)

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward Van Der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso De Mello

    2016-02-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots.

  10. Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors.

    PubMed

    Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko

    2015-01-01

    Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks. PMID:26404010

  11. Single-Photon-Resolved Cross-Kerr Interaction for Autonomous Stabilization of Photon-Number States.

    PubMed

    Holland, E T; Vlastakis, B; Heeres, R W; Reagor, M J; Vool, U; Leghtas, Z; Frunzio, L; Kirchmair, G; Devoret, M H; Mirrahimi, M; Schoelkopf, R J

    2015-10-30

    Quantum states can be stabilized in the presence of intrinsic and environmental losses by either applying an active feedback condition on an ancillary system or through reservoir engineering. Reservoir engineering maintains a desired quantum state through a combination of drives and designed entropy evacuation. We propose and implement a quantum-reservoir engineering protocol that stabilizes Fock states in a microwave cavity. This protocol is realized with a circuit quantum electrodynamics platform where a Josephson junction provides direct, nonlinear coupling between two superconducting waveguide cavities. The nonlinear coupling results in a single-photon-resolved cross-Kerr effect between the two cavities enabling a photon-number-dependent coupling to a lossy environment. The quantum state of the microwave cavity is discussed in terms of a net polarization and is analyzed by a measurement of its steady state Wigner function. PMID:26565448

  12. Optimised quantum hacking of superconducting nanowire single-photon detectors

    NASA Astrophysics Data System (ADS)

    Tanner, Michael G.; Makarov, Vadim; Hadfield, Robert H.

    2014-03-01

    We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack.

  13. Strong Single-Photon Coupling in Superconducting Quantum Magnetomechanics

    NASA Astrophysics Data System (ADS)

    Via, Guillem; Kirchmair, Gerhard; Romero-Isart, Oriol

    2015-04-01

    We show that the inductive coupling between the quantum mechanical motion of a superconducting microcantilever and a flux-dependent microwave quantum circuit can attain the strong single-photon nanomechanical coupling regime with feasible experimental parameters. We propose to use a superconducting strip, which is in the Meissner state, at the tip of a cantilever. A pickup coil collects the flux generated by the sheet currents induced by an external quadrupole magnetic field centered at the strip location. The position-dependent magnetic response of the superconducting strip, enhanced by both diamagnetism and demagnetizing effects, leads to a strong magnetomechanical coupling to quantum circuits.

  14. High bit rate germanium single photon detectors for 1310nm

    NASA Astrophysics Data System (ADS)

    Seamons, J. A.; Carroll, M. S.

    2008-04-01

    There is increasing interest in development of high speed, low noise and readily fieldable near infrared (NIR) single photon detectors. InGaAs/InP Avalanche photodiodes (APD) operated in Geiger mode (GM) are a leading choice for NIR due to their preeminence in optical networking. After-pulsing is, however, a primary challenge to operating InGaAs/InP single photon detectors at high frequencies1. After-pulsing is the effect of charge being released from traps that trigger false ("dark") counts. To overcome this problem, hold-off times between detection windows are used to allow the traps to discharge to suppress after-pulsing. The hold-off time represents, however, an upper limit on detection frequency that shows degradation beginning at frequencies of ~100 kHz in InGaAs/InP. Alternatively, germanium (Ge) single photon avalanche photodiodes (SPAD) have been reported to have more than an order of magnitude smaller charge trap densities than InGaAs/InP SPADs2, which allowed them to be successfully operated with passive quenching2 (i.e., no gated hold off times necessary), which is not possible with InGaAs/InP SPADs, indicating a much weaker dark count dependence on hold-off time consistent with fewer charge traps. Despite these encouraging results suggesting a possible higher operating frequency limit for Ge SPADs, little has been reported on Ge SPAD performance at high frequencies presumably because previous work with Ge SPADs has been discouraged by a strong demand to work at 1550 nm. NIR SPADs require cooling, which in the case of Ge SPADs dramatically reduces the quantum efficiency of the Ge at 1550 nm. Recently, however, advantages to working at 1310 nm have been suggested which combined with a need to increase quantum bit rates for quantum key distribution (QKD) motivates examination of Ge detectors performance at very high detection rates where InGaAs/InP does not perform as well. Presented in this paper are measurements of a commercially available Ge APD

  15. Optimised quantum hacking of superconducting nanowire single-photon detectors.

    PubMed

    Tanner, Michael G; Makarov, Vadim; Hadfield, Robert H

    2014-03-24

    We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack. PMID:24664022

  16. Multi-group dynamic quantum secret sharing with single photons

    NASA Astrophysics Data System (ADS)

    Liu, Hongwei; Ma, Haiqiang; Wei, Kejin; Yang, Xiuqing; Qu, Wenxiu; Dou, Tianqi; Chen, Yitian; Li, Ruixue; Zhu, Wu

    2016-07-01

    In this letter, we propose a novel scheme for the realization of single-photon dynamic quantum secret sharing between a boss and three dynamic agent groups. In our system, the boss can not only choose one of these three groups to share the secret with, but also can share two sets of independent keys with two groups without redistribution. Furthermore, the security of communication is enhanced by using a control mode. Compared with previous schemes, our scheme is more flexible and will contribute to a practical application.

  17. Inhomogeneous critical current in nanowire superconducting single-photon detectors

    SciTech Connect

    Gaudio, R. Hoog, K. P. M. op 't; Zhou, Z.; Sahin, D.; Fiore, A.

    2014-12-01

    A superconducting thin film with uniform properties is the key to realize nanowire superconducting single-photon detectors (SSPDs) with high performance and high yield. To investigate the uniformity of NbN films, we introduce and characterize simple detectors consisting of short nanowires with length ranging from 100 nm to 15 μm. Our nanowires, contrary to meander SSPDs, allow probing the homogeneity of NbN at the nanoscale. Experimental results, endorsed by a microscopic model, show the strongly inhomogeneous nature of NbN films on the sub-100 nm scale.

  18. Quantum Information Science with Single Atoms and Photons

    NASA Astrophysics Data System (ADS)

    Kimble, H. J.

    2003-03-01

    Cavity quantum electrodynamics (QED) offers powerful possibilities for the deterministic control of atom-photon interactions quantum by quantum [1]. Indeed, modern experiments in cavity QED have achieved the exceptional circumstance of strong coupling, for which single quanta can profoundly impact the dynamics of the atom-cavity system. The diverse accomplishments of this field set the stage for advances into yet broader frontiers in quantum information science for which cavity QED offers unique advantages, including the creation of quantum networks [2]. The primary technical challenge on the road toward such scientific goals is the need to trap and localize atoms within a cavity in a setting suitable for strong coupling. Two separate experiments in our group have achieved significant milestones in this quest, namely the real-time trapping and tracking of single atoms in cavity QED [3-5]. In one experiment, an atom is trapped by an auxiliary field that functions as a far-detuned dipole-force trap (FORT) [3,4], with trap lifetime 3s, which should be compared to the nanosecond time scale for internal dynamics of the atom-cavity system. In a second experiment, we rely upon light forces at the single-photon level to trap a single atom within the cavity mode [5]. As illustrated by the movies available at http://www.its.caltech.edu/ qoptics/atomorbits/, these reconstructions reveal single atoms bound in orbit by the mechanical forces associated with single photons, and realize a new form of microscopy. Over the duration of the observation, the sensitivity is near the standard quantum limit for sensing the motion of a Cesium atom. This work is supported by the NSF, by the Caltech MURI for Quantum Networks administered by the ARO, and by the ONR. 1. For a review, see contributions in the Special Issue of Physica Scripta T76 (1998). 2. J. I. Cirac, S. J. van Enk, P. Zoller, H. J. Kimble, and H. Mabuchi, Physica Scripta T76, 223 (1998). 3. J. Ye, D. W. Vernooy, and H. J

  19. Single-photon non-linear optics with a quantum dot in a waveguide

    PubMed Central

    Javadi, A.; Söllner, I.; Arcari, M.; Hansen, S. Lindskov; Midolo, L.; Mahmoodian, S.; Kiršanskė, G; Pregnolato, T.; Lee, E. H.; Song, J. D.; Stobbe, S.; Lodahl, P.

    2015-01-01

    Strong non-linear interactions between photons enable logic operations for both classical and quantum-information technology. Unfortunately, non-linear interactions are usually feeble and therefore all-optical logic gates tend to be inefficient. A quantum emitter deterministically coupled to a propagating mode fundamentally changes the situation, since each photon inevitably interacts with the emitter, and highly correlated many-photon states may be created. Here we show that a single quantum dot in a photonic-crystal waveguide can be used as a giant non-linearity sensitive at the single-photon level. The non-linear response is revealed from the intensity and quantum statistics of the scattered photons, and contains contributions from an entangled photon–photon bound state. The quantum non-linearity will find immediate applications for deterministic Bell-state measurements and single-photon transistors and paves the way to scalable waveguide-based photonic quantum-computing architectures. PMID:26492951

  20. Single photon lidar demonstrator for asteroid rendezvous missions

    NASA Astrophysics Data System (ADS)

    Vacek, Michael; Michalek, Vojtech; Peca, Marek; Prochazka, Ivan; Blazej, Josef; Djurovic, Goran

    2015-01-01

    We present compact single photon lidar demonstrator dedicated for asteroid rendezvous missions. The instrument provides crucial data on altitude and terrain profile for altitudes exceeding 5km with a precision of less than 10 cm fulfilling the Rayleigh criterion. Transmitter and receiver optics designs are discussed, control and processing electronics based on a single rad-hard compatible FPGA (Field Programmable Gate Array) is analyzed. The FPGA electronics subsystems are TDC (Time-to-Digit Converter), laser trigger pulse generator and gate generator. Indoor calibration procedures of the whole demonstrator chain are proposed and evaluated. The calibration covers positioning of receiver and transmitter optics related to detector and laser, aligning of transmitter and receiver optical common paths. The retrieving strategy of terrain elevation profile is proposed and via indoor tests validated. Theory for surface slope and scanning is established, simulation and measurement results are compared and discussed.

  1. Single photon counting pixel detectors for synchrotron radiation experiments

    NASA Astrophysics Data System (ADS)

    Toyokawa, H.; Broennimann, Ch.; Eikenberry, E. F.; Henrich, B.; Kawase, M.; Kobas, M.; Kraft, P.; Sato, M.; Schmitt, B.; Suzuki, M.; Tanida, H.; Uruga, T.

    2010-11-01

    At the Paul Scherrer Institute PSI an X-ray single photon counting pixel detector (PILATUS) based on the hybrid-pixel detector technology was developed in collaboration with SPring-8. The detection element is a 320 or 450 μm thick silicon sensor forming pixelated pn-diodes with a pitch of 172 μm×172 μm. An array of 2×8 custom CMOS readout chips are indium bump-bonded to the sensor, which leads to 33.5 mm×83.8 mm detective area. Each pixel contains a charge-sensitive amplifier, a single level discriminator and a 20 bit counter. This design realizes a high dynamic range, short readout time of less than 3 ms, a high framing rate of over 200 images per second and an excellent point-spread function. The maximum counting rate achieves more than 2×10 6 X-rays/s/pixel.

  2. Performance of single-photon-counting PILATUS detector modules

    PubMed Central

    Kraft, P.; Bergamaschi, A.; Broennimann, Ch.; Dinapoli, R.; Eikenberry, E. F.; Henrich, B.; Johnson, I.; Mozzanica, A.; Schlepütz, C. M.; Willmott, P. R.; Schmitt, B.

    2009-01-01

    PILATUS is a silicon hybrid pixel detector system, operating in single-photon-counting mode, that has been developed at the Paul Scherrer Institut for the needs of macromolecular crystallography at the Swiss Light Source (SLS). A calibrated PILATUS module has been characterized with monochromatic synchrotron radiation. The influence of charge sharing on the count rate and the overall energy resolution of the detector were investigated. The dead-time of the system was determined using the attenuated direct synchrotron beam. A single module detector was also tested in surface diffraction experiments at the SLS, whereby its performance regarding fluorescence suppression and saturation tolerance were evaluated, and have shown to greatly improve the sensitivity, reliability and speed of surface diffraction data acquisition. PMID:19395800

  3. Single-Photon Superradiance from a Quantum Dot.

    PubMed

    Tighineanu, Petru; Daveau, Raphaël S; Lehmann, Tau B; Beere, Harvey E; Ritchie, David A; Lodahl, Peter; Stobbe, Søren

    2016-04-22

    We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron and the hole comprising the exciton gives rise to an anharmonic spectrum, which we exploit to prepare the superradiant quantum state deterministically with a laser pulse. We observe a fivefold enhancement of the oscillator strength compared to conventional quantum dots. The enhancement is limited by the base temperature of our cryostat and may lead to oscillator strengths above 1000 from a single quantum emitter at optical frequencies. PMID:27152804

  4. Single-Photon Superradiance from a Quantum Dot

    NASA Astrophysics Data System (ADS)

    Tighineanu, Petru; Daveau, Raphaël S.; Lehmann, Tau B.; Beere, Harvey E.; Ritchie, David A.; Lodahl, Peter; Stobbe, Søren

    2016-04-01

    We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron and the hole comprising the exciton gives rise to an anharmonic spectrum, which we exploit to prepare the superradiant quantum state deterministically with a laser pulse. We observe a fivefold enhancement of the oscillator strength compared to conventional quantum dots. The enhancement is limited by the base temperature of our cryostat and may lead to oscillator strengths above 1000 from a single quantum emitter at optical frequencies.

  5. Single-photon sensitive light-in-fight imaging.

    PubMed

    Gariepy, Genevieve; Krstajić, Nikola; Henderson, Robert; Li, Chunyong; Thomson, Robert R; Buller, Gerald S; Heshmat, Barmak; Raskar, Ramesh; Leach, Jonathan; Faccio, Daniele

    2015-01-01

    The ability to record images with extreme temporal resolution enables a diverse range of applications, such as fluorescence lifetime imaging, time-of-flight depth imaging and characterization of ultrafast processes. Recently, ultrafast imaging schemes have emerged, which require either long acquisition times or raster scanning and have a requirement for sufficient signal that can only be achieved when light is reflected off an object or diffused by a strongly scattering medium. Here we present a demonstration of the potential of single-photon detector arrays for visualization and rapid characterization of events evolving on picosecond time scales. The single-photon sensitivity, temporal resolution and full-field imaging capability enables the observation of light-in-flight in air, as well as the measurement of laser-induced plasma formation and dynamics in its natural environment. The extreme sensitivity and short acquisition times pave the way for real-time imaging of ultrafast processes or visualization and tracking of objects hidden from view. PMID:25626147

  6. Single-photon sensitive light-in-fight imaging

    NASA Astrophysics Data System (ADS)

    Gariepy, Genevieve; Krstajić, Nikola; Henderson, Robert; Li, Chunyong; Thomson, Robert R.; Buller, Gerald S.; Heshmat, Barmak; Raskar, Ramesh; Leach, Jonathan; Faccio, Daniele

    2015-01-01

    The ability to record images with extreme temporal resolution enables a diverse range of applications, such as fluorescence lifetime imaging, time-of-flight depth imaging and characterization of ultrafast processes. Recently, ultrafast imaging schemes have emerged, which require either long acquisition times or raster scanning and have a requirement for sufficient signal that can only be achieved when light is reflected off an object or diffused by a strongly scattering medium. Here we present a demonstration of the potential of single-photon detector arrays for visualization and rapid characterization of events evolving on picosecond time scales. The single-photon sensitivity, temporal resolution and full-field imaging capability enables the observation of light-in-flight in air, as well as the measurement of laser-induced plasma formation and dynamics in its natural environment. The extreme sensitivity and short acquisition times pave the way for real-time imaging of ultrafast processes or visualization and tracking of objects hidden from view.

  7. Single-photon-level quantum image memory based on cold atomic ensembles

    PubMed Central

    Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Guo, Guang-Can

    2013-01-01

    A quantum memory is a key component for quantum networks, which will enable the distribution of quantum information. Its successful development requires storage of single-photon light. Encoding photons with spatial shape through higher-dimensional states significantly increases their information-carrying capability and network capacity. However, constructing such quantum memories is challenging. Here we report the first experimental realization of a true single-photon-carrying orbital angular momentum stored via electromagnetically induced transparency in a cold atomic ensemble. Our experiments show that the non-classical pair correlation between trigger photon and retrieved photon is retained, and the spatial structure of input and retrieved photons exhibits strong similarity. More importantly, we demonstrate that single-photon coherence is preserved during storage. The ability to store spatial structure at the single-photon level opens the possibility for high-dimensional quantum memories. PMID:24084711

  8. Single-photon-level quantum image memory based on cold atomic ensembles

    NASA Astrophysics Data System (ADS)

    Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Guo, Guang-Can

    2013-10-01

    A quantum memory is a key component for quantum networks, which will enable the distribution of quantum information. Its successful development requires storage of single-photon light. Encoding photons with spatial shape through higher-dimensional states significantly increases their information-carrying capability and network capacity. However, constructing such quantum memories is challenging. Here we report the first experimental realization of a true single-photon-carrying orbital angular momentum stored via electromagnetically induced transparency in a cold atomic ensemble. Our experiments show that the non-classical pair correlation between trigger photon and retrieved photon is retained, and the spatial structure of input and retrieved photons exhibits strong similarity. More importantly, we demonstrate that single-photon coherence is preserved during storage. The ability to store spatial structure at the single-photon level opens the possibility for high-dimensional quantum memories.

  9. The photonic nanowire: an emerging platform for highly efficient single-photon sources for quantum information applications

    NASA Astrophysics Data System (ADS)

    Gregersen, Niels; Munsch, Mathieu; Malik, Nitin S.; Bleuse, Joël.; Dupuy, Emmanuel; Delga, Adrien; Mørk, Jesper; Gérard, Jean-Michel; Claudon, Julien

    2013-05-01

    Efficient coupling between a localized quantum emitter and a well defined optical channel represents a powerful route to realize single-photon sources and spin-photon interfaces. The tailored fiber-like photonic nanowire embedding a single quantum dot has recently demonstrated an appealing potential. However, the device requires a delicate, sharp needle-like taper with performance sensitive to minute geometrical details. To overcome this limitation we demonstrate the photonic trumpet, exploiting an opposite tapering strategy. The trumpet features a strongly Gaussian far-field emission. A first implementation of this strategy has lead to an ultra-bright single-photon source with a first-lens external efficiency of 0.75 +/- 0.1 and a predicted coupling to a Gaussian beam of 0.61 +/- 0.08.

  10. Entangled absorption of a single photon with a single spin in diamond.

    PubMed

    Kosaka, Hideo; Niikura, Naeko

    2015-02-01

    Quantum entanglement, a key resource for quantum information science, is inherent in a solid. It has been recently shown that entanglement between a single optical photon and a single spin qubit in a solid is generated via spontaneous emission. However, entanglement generation by measurement is rather essential for quantum operations. We here show that the physics behind the entangled emission can be time reversed to demonstrate entangled absorption mediated by an inherent spin-orbit entanglement in a single nitrogen vacancy center in diamond. Optical arbitrary spin state preparation and complete spin state tomography reveal the fidelity of the entangled absorption to be 95%. With the entangled emission and absorption of a photon, materials can be spontaneously entangled or swap their quantum state based on the quantum teleportation scheme. PMID:25699440

  11. Analysis of photonic logic gates based on single hexagonal-lattice photonic crystal ring resonator

    NASA Astrophysics Data System (ADS)

    Jiang, Junzhen; Qiang, Zexuan; Xu, Xiaofu; Chen, Xiyao

    2011-01-01

    We devised a new configuration of optical logic gates based on a single hexagonal-lattice photonic crystal ring resonator (PCRR) composed of two-dimensional (2D) cylindrical silicon rods in air. The modal behavior of the proposed logic gates was comprehensively analyzed with a topology optimization technique based on the principle of beam interference and perturbation theory. It was then numerically verified by using a 2D finite-difference time-domain technique. The predictions have a very good agreement with the numerical results. This new single PCRR can really function as NOT and NOR gates. And the logic ``0'' and ``1'' of the hexagonal ring can be defined as less than 8% and greater than 86%, respectively, much better than earlier reported square-lattice results.

  12. Single-photon events in the DELPHI experiment

    NASA Astrophysics Data System (ADS)

    Harris, Elisabeth Falk

    1998-08-01

    A series of studies pertaining to the STIC calorimeter at the DELPHI experiment at LEP is presented, and a new generation of fast wire scanners for emittance measurements at PS is described. The STIC studies are centered around a single-photon analysis, in which the reaction e+c/sp-/to/gamma + invisible particles was studied at center-of-mass energies of 161, 172 and 183 GeV. The cross section thus obtained was used to measure the number of neutrino families, and also to set limits on physics reactions occuring outside the framework of the Standard Model. The single-photon analysis is rendered difficult by an abundance of off-energy electron background. This type of background was examined in a separate series of Monte Carlo simulations, which are also reported. The STIC calorimeter modules have been equipped with a tracking device in the form of silicon-strip detectors, in order to improve the rejection of off-energy electrons in single-proton analyses. Results from a study of the performance of these detectors are presented. A method to reduce coherent noise in the silicon-strip detectors is also described. A new generation of fast wire scanners was installed at PS in 1994. The wire scanners are an important tool for measuring transverse beam profiles, from which transverse emittances are derived. An upgrade of a previous set of wire scanners was essential in order to obtain a reliable instrument that provides highly accurate emittance measurements, in particular in view of the future use of the PS accelerator complex as part of the injector chain for LHC. A presentation is given of the new instrument.

  13. Single Photon Counting Performance and Noise Analysis of CMOS SPAD-Based Image Sensors.

    PubMed

    Dutton, Neale A W; Gyongy, Istvan; Parmesan, Luca; Henderson, Robert K

    2016-01-01

    SPAD-based solid state CMOS image sensors utilising analogue integrators have attained deep sub-electron read noise (DSERN) permitting single photon counting (SPC) imaging. A new method is proposed to determine the read noise in DSERN image sensors by evaluating the peak separation and width (PSW) of single photon peaks in a photon counting histogram (PCH). The technique is used to identify and analyse cumulative noise in analogue integrating SPC SPAD-based pixels. The DSERN of our SPAD image sensor is exploited to confirm recent multi-photon threshold quanta image sensor (QIS) theory. Finally, various single and multiple photon spatio-temporal oversampling techniques are reviewed. PMID:27447643

  14. Single Photon Counting Performance and Noise Analysis of CMOS SPAD-Based Image Sensors

    PubMed Central

    Dutton, Neale A. W.; Gyongy, Istvan; Parmesan, Luca; Henderson, Robert K.

    2016-01-01

    SPAD-based solid state CMOS image sensors utilising analogue integrators have attained deep sub-electron read noise (DSERN) permitting single photon counting (SPC) imaging. A new method is proposed to determine the read noise in DSERN image sensors by evaluating the peak separation and width (PSW) of single photon peaks in a photon counting histogram (PCH). The technique is used to identify and analyse cumulative noise in analogue integrating SPC SPAD-based pixels. The DSERN of our SPAD image sensor is exploited to confirm recent multi-photon threshold quanta image sensor (QIS) theory. Finally, various single and multiple photon spatio-temporal oversampling techniques are reviewed. PMID:27447643

  15. Radiation burst from a single γ-photon field

    NASA Astrophysics Data System (ADS)

    Shakhmuratov, R. N.; Vagizov, F.; Kocharovskaya, O.

    2011-10-01

    The radiation burst from a single γ-photon field interacting with a dense resonant absorber is studied theoretically and experimentally. This effect was discovered for the fist time by P. Helisto [Phys. Rev. Lett. PRLTAO0031-900710.1103/PhysRevLett.66.203766, 2037 (1991)] and it was named the “gamma echo.” The echo is generated by a 180∘ phase shift of the incident radiation field, attained by an abrupt change of the position of the absorber with respect to the radiation source during the coherence time of the photon wave packet. Three distinguishing cases of the gamma echo are considered; i.e., the photon is in exact resonance with the absorber, close to resonance (on the slope of the absorption line), and far from resonance (on the far wings of the resonance line). In resonance the amplitude of the radiation burst is two times larger than the amplitude of the input radiation field just before its phase shift. This burst was explained by Helisto as a result of constructive interference of the coherently scattered field with the phase-shifted input field, both having almost the same amplitude. We found that out of resonance the scattered radiation field acquires an additional component with almost the same amplitude as the amplitude of the incident radiation field. The phase of the additional field depends on the optical thickness of the absorber and resonant detuning. Far from resonance this field interferes destructively with the phase-shifted incident radiation field and radiation quenching is observed. Close to resonance the three fields interfere constructively and the amplitude of the radiation burst is three times larger than the amplitude of the input radiation field.

  16. Radiation burst from a single {gamma}-photon field

    SciTech Connect

    Shakhmuratov, R. N.; Vagizov, F.; Kocharovskaya, O.

    2011-10-15

    The radiation burst from a single {gamma}-photon field interacting with a dense resonant absorber is studied theoretically and experimentally. This effect was discovered for the fist time by P. Helisto et al.[Phys. Rev. Lett. 66, 2037 (1991)] and it was named the ''gamma echo''. The echo is generated by a 180 Degree-Sign phase shift of the incident radiation field, attained by an abrupt change of the position of the absorber with respect to the radiation source during the coherence time of the photon wave packet. Three distinguishing cases of the gamma echo are considered; i.e., the photon is in exact resonance with the absorber, close to resonance (on the slope of the absorption line), and far from resonance (on the far wings of the resonance line). In resonance the amplitude of the radiation burst is two times larger than the amplitude of the input radiation field just before its phase shift. This burst was explained by Helisto et al. as a result of constructive interference of the coherently scattered field with the phase-shifted input field, both having almost the same amplitude. We found that out of resonance the scattered radiation field acquires an additional component with almost the same amplitude as the amplitude of the incident radiation field. The phase of the additional field depends on the optical thickness of the absorber and resonant detuning. Far from resonance this field interferes destructively with the phase-shifted incident radiation field and radiation quenching is observed. Close to resonance the three fields interfere constructively and the amplitude of the radiation burst is three times larger than the amplitude of the input radiation field.

  17. Experimental studies of single-photon photodetachment of atomic anions

    NASA Astrophysics Data System (ADS)

    Duvvuri, Srividya S.

    Laser photodetachment electron spectroscopy (LPES) has been used to study the structure of the terbium anion. The data was analyzed assuming that the terbium anion forms in dysprosium-like states. Using this assumption, the electron affinity of Tb([Xe]4f96s 2 6 Ho15/2 ) equals 1.98 +/- 0.10 eV, and the ground state of the terbium anion is assigned to the Dy-like Tb-([Xe]4f 106s2 5I 8) electronic configuration. At lust two bound excited states of Tb - are also evident in the photoelectron kinetic energy spectra, with binding energies of 0.449 +/- 0.01 and 1.67 +/- 0.07 eV relative to the Tb(6 Ho15/2 ) ground state. The energy scale of each Tb- photoelectron spectrum way calibrated using reference photoelectron peaks from 12 C-, 16O- and 23Na-, which have well known binding energies [1]. Photoelectron angular distribution measurements following the single-photon photodetachment of the lanthanide anions Tb- and Lu - are also presented. The asymmetry parameters were determined from the non-linear least-square fits of the photoelectron yields as a function of the angle between the photon polarization vector and the photoelectron momentum vector of the collected photoelectrons. The measurements indicated the single-photon photodetachment process hnu + Tb -([Xe]4f106s 2 5I8) → Tb([Xe]4 f96s2 6) Ho15/2 + e - has beta values of 1.51 +/- 0.08 and 1.35 +/- 0.08 at wavelengths of 514.5 and 488 nm, respectively. For Lu -, the fine-structure resolved photodetachment process hnu +Lu-([Xe]4f146s 26p5d 1D 2) → Lu([Xe]4f145 d6s2 2D 3/2) + e-, has been measured at wavelength of 532 nm yielding beta = 0.8 +/- 0.1, supporting the assertion that Lu - forms via the attachment of a 6p-electron to the neutral Lu atom [2]. Finally, photodetachment cross sections and the angular distributions of photo-electrons produced by the single-photon detachment of the Fe - and Cu- have also been measured at discrete visible photon wavelengths. From the measured photodetachment cross sections, the

  18. Direct Photonic-Plasmonic Coupling and Routing in Single Nanowires

    SciTech Connect

    Yan, Rouxue; Pausauskie, Peter; Huang, Jiaxing; Yang, Piedong

    2009-10-20

    Metallic nanoscale structures are capable of supporting surface plasmon polaritons (SPPs), propagating collective electron oscillations with tight spatial confinement at the metal surface. SPPs represent one of the most promising structures to beat the diffraction limit imposed by conventional dielectric optics. Ag nano wires have drawn increasing research attention due to 2D sub-100 nm mode confinement and lower losses as compared with fabricated metal structures. However, rational and versatile integration of Ag nanowires with other active and passive optical components, as well as Ag nanowire based optical routing networks, has yet to be achieved. Here, we demonstrate that SPPs can be excited simply by contacting a silver nanowire with a SnO2 nanoribbon that serves both as an unpolarized light source and a dielectric waveguide. The efficient coupling makes it possible to measure the propagation-distance-dependent waveguide spectra and frequency-dependent propagation length on a single Ag nanowire. Furthermore, we have demonstrated prototypical photonic-plasmonic routing devices, which are essential for incorporating low-loss Ag nanowire waveguides as practical components into high-capacity photonic circuits.

  19. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits.

    PubMed

    Yu, Leo; Natarajan, Chandra M; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S; Tanner, Michael G; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H; Fejer, Martin M; Yamamoto, Yoshihisa

    2015-01-01

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances. PMID:26597223

  20. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

    PubMed Central

    Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

    2015-01-01

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances. PMID:26597223

  1. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

    NASA Astrophysics Data System (ADS)

    Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

    2015-11-01

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

  2. Heralded single-photon source utilizing highly nondegenerate, spectrally factorable spontaneous parametric downconversion.

    PubMed

    Kaneda, Fumihiro; Garay-Palmett, Karina; U'Ren, Alfred B; Kwiat, Paul G

    2016-05-16

    We report on the generation of an indistinguishable heralded single-photon state, using highly nondegenerate spontaneous parametric downconversion (SPDC). Spectrally factorable photon pairs can be generated by incorporating a broadband pump pulse and a group-velocity matching (GVM) condition in a periodically-poled potassium titanyl phosphate (PPKTP) crystal. The heralding photon is in the near IR, close to the peak detection efficiency of off-the-shelf Si single-photon detectors; meanwhile, the heralded photon is in the telecom L-band where fiber losses are at a minimum. We observe spectral factorability of the SPDC source and consequently high purity (90%) of the produced heralded single photons by several different techniques. Because this source can also realize a high heralding efficiency (> 90%), it would be suitable for time-multiplexing techniques, enabling a pseudo-deterministic single-photon source, a critical resource for optical quantum information and communication technology. PMID:27409894

  3. Single photon emission computed tomography (SPECT) in epilepsy

    SciTech Connect

    Leroy, R.F.

    1991-12-31

    Epilepsy is a common neurologic disorder which has just begun to be studied with single photon emission computerized tomography (SPECT). Epilepsy usually is studied with electroencephalographic (EEG) techniques that demonstrate the physiologic changes that occur during seizures, and with neuroimaging techniques that show the brain structures where seizures originate. Neither method alone has been adequate to describe the pathophysiology of the patient with epilepsy. EEG techniques lack anatomic sensitivity, and there are no structural abnormalities shown by neuroimaging which are specific for epilepsy. Functional imaging (FI) has developed as a physiologic tool with anatomic sensitivity, and SPECT has been promoted as a FI technique because of its potentially wide availability. However, SPECT is early in its development and its clinical utility for epilepsy still has to be demonstrated. To understand this role of SPECT, consideration must be given to the pathophysiology of epilepsy, brain physiology, types of seizure, epileptic syndromes, and the SPECT technique itself. 44 refs., 2 tabs.

  4. Single photon emission computed tomography in AIDS dementia complex

    SciTech Connect

    Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

    1988-08-01

    Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder.

  5. Mars laser altimeter based on a single photon ranging technique

    NASA Technical Reports Server (NTRS)

    Prochazka, Ivan; Hamal, Karel; Sopko, B.; Pershin, S.

    1993-01-01

    The Mars 94/96 Mission will carry, among others things, the balloon probe experiment. The balloon with the scientific cargo in the gondola underneath will drift in the Mars atmosphere, its altitude will range from zero, in the night, up to 5 km at noon. The accurate gondola altitude will be determined by an altimeter. As the Balloon gondola mass is strictly limited, the altimeter total mass and power consumption are critical; maximum allowed is a few hundred grams a few tens of mWatts of average power consumption. We did propose, design, and construct the laser altimeter based on the single photon ranging technique. Topics covered include the following: principle of operation, altimeter construction, and ground tests.

  6. Discriminating single-photon states unambiguously in high dimensions.

    PubMed

    Agnew, Megan; Bolduc, Eliot; Resch, Kevin J; Franke-Arnold, Sonja; Leach, Jonathan

    2014-07-11

    The ability to uniquely identify a quantum state is integral to quantum science, but for nonorthogonal states, quantum mechanics precludes deterministic, error-free discrimination. However, using the nondeterministic protocol of unambiguous state discrimination enables the error-free differentiation of states, at the cost of a lower frequency of success. We discriminate experimentally between nonorthogonal, high-dimensional states encoded in single photons; our results range from dimension d=2 to d=14. We quantify the performance of our method by comparing the total measured error rate to the theoretical rate predicted by minimum-error state discrimination. For the chosen states, we find a lower error rate by more than 1 standard deviation for dimensions up to d=12. This method will find immediate application in high-dimensional implementations of quantum information protocols, such as quantum cryptography. PMID:25062151

  7. Efficient isotope separation by single-photon atomic sorting

    SciTech Connect

    Jerkins, M.; Chavez, I.; Raizen, M. G.; Even, U.

    2010-09-15

    We propose a general and scalable approach to isotope separation. The method is based on an irreversible change of the mass-to-magnetic moment ratio of a particular isotope in an atomic beam, followed by a magnetic multipole whose gradients deflect and guide the atoms. The underlying mechanism is a reduction of the entropy of the beam by the information of a single scattered photon for each atom that is separated. We numerically simulate isotope separation for a range of examples, which demonstrate this technique's general applicability to almost the entire periodic table. The practical importance of the proposed method is that large-scale isotope separation should be possible, using ordinary inexpensive magnets and the existing technologies of supersonic beams and lasers.

  8. Single-photon cooling in a wedge billiard

    SciTech Connect

    Choi, S.; Sundaram, B.; Raizen, M. G.

    2010-09-15

    Single-photon cooling (SPC), noted for its potential as a versatile method for cooling a variety of atomic species, has recently been demonstrated experimentally. In this paper, we study possible ways to improve the performance of SPC by applying it to atoms trapped inside a wedge billiard. The main feature of the wedge billiard for atoms, also experimentally realized recently, is that the nature of atomic trajectories within it changes from stable periodic orbit to random chaotic motion with the change in wedge angle. We find that a high cooling efficiency is possible in this system with a relatively weak dependence on the wedge angle and that chaotic dynamics, rather than a regular orbit, is more desirable for enhancing the performance of SPC.

  9. Athermal avalanche in bilayer superconducting nanowire single-photon detectors

    NASA Astrophysics Data System (ADS)

    Verma, V. B.; Lita, A. E.; Stevens, M. J.; Mirin, R. P.; Nam, S. W.

    2016-03-01

    We demonstrate that two superconducting nanowires separated by a thin insulating barrier can undergo an avalanche process. In this process, Joule heating caused by a photodetection event in one nanowire and the associated production of athermal phonons which are transmitted through the barrier cause the transition of the adjacent nanowire from the superconducting to the normal state. We show that this process can be utilized in the fabrication of superconducting nanowire single photon detectors to improve the signal-to-noise ratio, reduce system jitter, maximize device area, and increase the external efficiency over a very broad range of wavelengths. Furthermore, the avalanche mechanism may provide a path towards a superconducting logic element based on athermal gating.

  10. Single-photon emission of two-level system via rapid adiabatic passage

    PubMed Central

    Miao, Qiang; Zheng, Yujun

    2016-01-01

    In this paper, we present a high quality single-photon source based on the two-level system undergoing rapid adiabatic passage (RAP). A trigger strategy (sweet region) is suggested to optimize the single-photon emission and explain a counter-intuitive phenomenon on the optimal parameters. The RAP strategy of single-photon source is robust against control error and environmental fluctuation. PMID:27601295

  11. Single-photon emission of two-level system via rapid adiabatic passage.

    PubMed

    Miao, Qiang; Zheng, Yujun

    2016-01-01

    In this paper, we present a high quality single-photon source based on the two-level system undergoing rapid adiabatic passage (RAP). A trigger strategy (sweet region) is suggested to optimize the single-photon emission and explain a counter-intuitive phenomenon on the optimal parameters. The RAP strategy of single-photon source is robust against control error and environmental fluctuation. PMID:27601295

  12. Single photon time transfer link model for GNSS satellites

    NASA Astrophysics Data System (ADS)

    Vacek, Michael; Michalek, Vojtech; Peca, Marek; Prochazka, Ivan; Blazej, Josef

    2015-05-01

    The importance of optical time transfer serving as a complement to traditional microwave links, has been attested for GNSSes and for scientific missions. Single photon time transfer (SPTT) is a process, allowing to compare (subtract) time readings of two distant clocks. Such a comparison may be then used to synchronize less accurate clock to a better reference, to perform clock characterization and calibration, to calculate mean time out of ensemble of several clocks, displaced in space. The single-photon time transfer is well established in field of space geodesy, being supported by passive retro-reflectors within space segment of five known GNSSes. A truly two-way, active terminals work aboard of Jason-2 (T2L2) - multiphoton operation, GNSS Beidou (Compass) - SPTT, and are going to be launched within recent ACES project (ELT) - SPTT, and GNSS GLONASS - multiphoton operation. However, there is still missing comprehensive theoretical model of two-way (using satellite receiver and retroreflector) SPTT link incorporating all crucial parameters of receiver (both ground and space segment receivers), transmitter, atmosphere effects on uplink and downlink path, influence of retroreflector. The input to calculation of SPTT link performance will be among others: link budget (distance, power, apertures, beam divergence, attenuation, scattering), propagating medium (atmosphere scintillation, beam wander, etc.), mutual Tx/Rx velocity, wavelength. The SPTT model will be evaluated without the properties of real components. These will be added in the further development. The ground-to-space SPTT link performance of typical scenarios are modeled. This work is a part of the ESA study "Comparison of optical time-transfer links."

  13. Single photon radioluminescence. I. Theory and spectroscopic properties.

    PubMed Central

    Bicknese, S; Shahrokh, Z; Shohet, S B; Verkman, A S

    1992-01-01

    The excitation of a fluorescent molecule by a beta-decay electron (radioluminescence) depends upon the electron energy, the distance between radioactive 'donor' and fluorescent 'acceptor', and the excitation characteristics and solvent environment of the fluorophore. The theory for calculation of single photon radioluminescence (SPR) signals is developed here; in the accompanying paper, measurement methods and biological applications are presented. To calculate the three-dimensional spatial profile for electron energy deposition in an aqueous environment, a Monte Carlo calculation was performed incorporating theories of electron energy distributions, energy loss due to interactions with matter, and deflections in electron motion due to collisions. For low energy beta emitters, 50% of energy deposition occurs within 0.63 micron (3H, 18.5 keV), 22 microns (14C, 156 keV), 25 microns (35S, 167 keV), and 260 microns (36Cl, 712 keV) of the radioisotope. In close proximity to the beta emitter (100 nm, 3H; 10 microns, 14C) the probability for fluorophore excitation is approximately proportional to the inverse square of the distance between the beta emitter and fluorophore. To investigate the other factors that determine the probability for fluorophore excitation, SPR measurements were carried out in solutions containing 3H and a series of fluorophores in different solvents. In water, the probability of fluorescence excitation was nearly proportional to the integrated absorbance over a > 1,000-fold variation in absorbances. The probability of fluorescence excitation was enhanced up to 2,600-fold when the fluorophore was in a "scintillant" aromatic or hydrocarbon solvent. SPR emission spectra were similar to fluorescence emission spectra obtained with photon excitation. The single photon signal due to Bremsstrahlung increased with wavelength in agreement with theory. The distance dependence for the SPR signal predicted by the model was in good agreement with measurements in

  14. Custom single-photon avalanche diode with integrated front-end for parallel photon timing applications

    NASA Astrophysics Data System (ADS)

    Cammi, C.; Panzeri, F.; Gulinatti, A.; Rech, I.; Ghioni, M.

    2012-03-01

    Emerged as a solid state alternative to photo multiplier tubes (PMTs), single-photon avalanche diodes (SPADs) are nowadays widely used in the field of single-photon timing applications. Custom technology SPADs assure remarkable performance, in particular a 10 counts/s dark count rate (DCR) at low temperature, a high photon detection efficiency (PDE) with a 50% peak at 550 nm and a 30 ps (full width at half maximum, FWHM) temporal resolution, even with large area devices, have been obtained. Over the past few years, the birth of novel techniques of analysis has led to the parallelization of the measurement systems and to a consequent increasing demand for the development of monolithic arrays of detectors. Unfortunately, the implementation of a multidimensional system is a challenging task from the electrical point of view; in particular, the avalanche current pick-up circuit, used to obtain the previously reported performance, has to be modified in order to enable high parallel temporal resolution, while minimizing the electrical crosstalk probability between channels. In the past, the problem has been solved by integrating the front-end electronics next to the photodetector, in order to reduce the parasitic capacitances and consequently the filtering action on the current signal of the SPAD, leading to an improvement of the timing jitter at higher threshold. This solution has been implemented by using standard complementary metal-oxide-semiconductor (CMOS) technologies, which, however, do not allow a complete control on the SPAD structure; for this reason the intrinsic performance of CMOS SPADs, such as DCR, PDE, and afterpulsing probability, are worse than those attainable with custom detectors. In this paper, we propose a pixel architecture, which enables the development of custom SPAD arrays in which every channel maintains the performance of the best single photodetector. The system relies on the integration of the timing signal pick-up circuit next to the

  15. Custom single-photon avalanche diode with integrated front-end for parallel photon timing applications.

    PubMed

    Cammi, C; Panzeri, F; Gulinatti, A; Rech, I; Ghioni, M

    2012-03-01

    Emerged as a solid state alternative to photo multiplier tubes (PMTs), single-photon avalanche diodes (SPADs) are nowadays widely used in the field of single-photon timing applications. Custom technology SPADs assure remarkable performance, in particular a 10 counts/s dark count rate (DCR) at low temperature, a high photon detection efficiency (PDE) with a 50% peak at 550 nm and a 30 ps (full width at half maximum, FWHM) temporal resolution, even with large area devices, have been obtained. Over the past few years, the birth of novel techniques of analysis has led to the parallelization of the measurement systems and to a consequent increasing demand for the development of monolithic arrays of detectors. Unfortunately, the implementation of a multidimensional system is a challenging task from the electrical point of view; in particular, the avalanche current pick-up circuit, used to obtain the previously reported performance, has to be modified in order to enable high parallel temporal resolution, while minimizing the electrical crosstalk probability between channels. In the past, the problem has been solved by integrating the front-end electronics next to the photodetector, in order to reduce the parasitic capacitances and consequently the filtering action on the current signal of the SPAD, leading to an improvement of the timing jitter at higher threshold. This solution has been implemented by using standard complementary metal-oxide-semiconductor (CMOS) technologies, which, however, do not allow a complete control on the SPAD structure; for this reason the intrinsic performance of CMOS SPADs, such as DCR, PDE, and afterpulsing probability, are worse than those attainable with custom detectors. In this paper, we propose a pixel architecture, which enables the development of custom SPAD arrays in which every channel maintains the performance of the best single photodetector. The system relies on the integration of the timing signal pick-up circuit next to the

  16. Single photons on-demand from light-hole excitons in strain-engineered quantum dots.

    PubMed

    Zhang, Jiaxiang; Huo, Yongheng; Rastelli, Armando; Zopf, Michael; Höfer, Bianca; Chen, Yan; Ding, Fei; Schmidt, Oliver G

    2015-01-14

    We demonstrate for the first time on-demand and wavelength-tunable single-photon emission from light-hole (LH) excitons in strain engineered GaAs quantum dots (QDs). The LH photon emission from tensile-strained GaAs QDs is systematically investigated with polarization-resolved, power-dependent photoluminescence spectroscopy, and photon-correlation measurements. By integrating QD-containing nanomembranes onto a piezo-actuator and driving single QDs with picosecond laser pulses, we achieve triggered and wavelength-tunable LH single-photon emission. Fourier transform spectroscopy is also performed, from which the coherence time of the LH single-photon emission is studied. We envision that this new type of LH exciton-based single-photon source (SPS) can be applied to realize an all-semiconductor based quantum interface in distributed quantum networks [Phys. Rev. Lett. 2008, 100, 096602]. PMID:25471544

  17. Single-photon routing by time-division phase modulation in a Sagnac interferometer

    NASA Astrophysics Data System (ADS)

    Zhou, Chunyuan; Wu, Guang; Ding, Liang'en; Zeng, Heping

    2003-07-01

    In this letter, we report the experimental demonstration of a single-photon router based on a time-division Sagnac interferometer, wherein differential phase shifts are applied on either the clockwise or counterclockwise quasi-single-photon pulses to determine the single photon interference and consequently output photon routing. High fidelity (>85%) of single-photon routing was demonstrated over a long-distance Sagnac loop. Stable performance was guaranteed by passive compensation of stress and temperature dependent drifts of the fiber-optic path. Experimental data show that time-division single-photon routing can be realized by controlling the applied electric pulses on the integrated phase modulators in the Sagnac loop, which makes this setup suitable for a practical quantum cryptography system.

  18. Interference with a quantum dot single-photon source and a laser at telecom wavelength

    SciTech Connect

    Felle, M.; Huwer, J. Stevenson, R. M.; Skiba-Szymanska, J.; Ward, M. B.; Shields, A. J.; Farrer, I.; Ritchie, D. A.; Penty, R. V.

    2015-09-28

    The interference of photons emitted by dissimilar sources is an essential requirement for a wide range of photonic quantum information applications. Many of these applications are in quantum communications and need to operate at standard telecommunication wavelengths to minimize the impact of photon losses and be compatible with existing infrastructure. Here, we demonstrate for the first time the quantum interference of telecom-wavelength photons from an InAs/GaAs quantum dot single-photon source and a laser; an important step towards such applications. The results are in good agreement with a theoretical model, indicating a high degree of indistinguishability for the interfering photons.

  19. Efficient routing of single photons by one atom and a microtoroidal cavity.

    PubMed

    Aoki, Takao; Parkins, A S; Alton, D J; Regal, C A; Dayan, Barak; Ostby, E; Vahala, K J; Kimble, H J

    2009-02-27

    Single photons from a coherent input are efficiently redirected to a separate output by way of a fiber-coupled microtoroidal cavity interacting with individual cesium atoms. By operating in an overcoupled regime for the input-output to a tapered fiber, our system functions as a quantum router with high efficiency for photon sorting. Single photons are reflected and excess photons transmitted, as confirmed by observations of photon antibunching (bunching) for the reflected (transmitted) light. Our photon router is robust against large variations of atomic position and input power, with the observed photon antibunching persisting for intracavity photon number 0.03 < or approximately similar n < or approximately similar 0.7. PMID:19257737

  20. Electrically pumped single-photon emission at room temperature from a single InGaN/GaN quantum dot

    SciTech Connect

    Deshpande, Saniya; Frost, Thomas; Hazari, Arnab; Bhattacharya, Pallab

    2014-10-06

    We demonstrate a semiconductor quantum dot based electrically pumped single-photon source operating at room temperature. Single photons emitted in the red spectral range from single In{sub 0.4}Ga{sub 0.6}N/GaN quantum dots exhibit a second-order correlation value g{sup (2)}(0) of 0.29, and fast recombination lifetime ∼1.3 ±0.3 ns at room temperature. The single-photon source can be driven at an excitation repetition rate of 200 MHz.

  1. Indistinguishable near-infrared single photons from an individual organic molecule

    NASA Astrophysics Data System (ADS)

    Trebbia, Jean-Baptiste; Tamarat, Philippe; Lounis, Brahim

    2010-12-01

    By using the zero-phonon line emission of an individual organic molecule, we realized a source of indistinguishable single photons in the near infrared. A Hong-Ou-Mandel interference experiment is performed and a two-photon coalescence probability higher than 50% at 2 K is obtained. The contribution of the temperature-dependent dephasing processes to the two-photon interference contrast is studied. We show that the molecule delivers nearly ideal indistinguishable single photons at the lowest temperatures when the dephasing is nearly lifetime limited. This source is used to generate postselected polarization-entangled photon pairs as a test bench for applications in quantum information.

  2. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    NASA Astrophysics Data System (ADS)

    Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus

    2016-06-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times.

  3. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    PubMed Central

    Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus

    2016-01-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times. PMID:27274604

  4. Single-photon scattering in an optomechanical Jaynes-Cummings model

    NASA Astrophysics Data System (ADS)

    Ng, K. H.; Law, C. K.

    2016-04-01

    We investigate an optomechanical system which realizes the Jaynes-Cummings (JC) model known in cavity QED. Such a system consists of a single photon and an optomechanical cavity with two optical cavity modes and one mechanical mode. Under the resonance condition when the mechanical frequency is close to the frequency difference between the optical modes, the photon and phonons can be strongly coupled. We present an analytic solution of single-photon scattering and show that the spectrum of the scattered photon exhibits excitation-number-dependent Rabi splitting of the JC model. In addition, we examine the response of the mechanical mode to a sequence of single photons, with one photon in the cavity at a time. We show that sequential photon scattering can efficiently excite the mechanical mode and generate sub-Poisson phonon statistics.

  5. Proceedings of clinical SPECT (single photon emission computed tomography) symposium

    SciTech Connect

    Not Available

    1986-09-01

    It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emission computed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have selected the key areas which demand awareness and attention in order to make SPECT operational in clinical practice. These include selection of equipment, details of uniformity correction, utilization of phantoms for equipment acceptance and quality assurance, the major aspect of algorithms, an understanding of filtered back projection and appropriate choice of filters and an awareness of the most commonly generated artifacts and how to recognize them. With respect to the acquisition and interpretation of organ images, the faculty will present information on the major aspects of hepatic, brain, cardiac, skeletal, and immunologic imaging techniques. Individual papers are processed separately for the data base. (TEM)

  6. Single-polarization hollow-core square photonic bandgap waveguide

    NASA Astrophysics Data System (ADS)

    Eguchi, Masashi; Tsuji, Yasuhide

    2016-07-01

    Materials with a periodic structure have photonic bandgaps (PBGs), in which light can not be guided within certain wavelength ranges; thus light can be confined within a low-index region by the bandgap effect. In this paper, rectangular-shaped hollow waveguides having waveguide-walls (claddings) using the PBG have been discussed. The design principle for HE modes of hollow-core rectangular PBG waveguides with a Bragg cladding consisting of alternating high- and low-index layers, based on a 1D periodic multilayer approximation for the Bragg cladding, is established and then a novel single-polarization hollow-core square PBG waveguide using the bandgap difference between two polarized waves is proposed. Our results demonstrated that a single-polarization guiding can be achieved by using the square Bragg cladding structure with different layer thickness ratios in the mutually orthogonal directions and the transmission loss of the guided mode in a designed hollow-core square PBG waveguide is numerically estimated to be 0.04 dB/cm.

  7. Single- and dual-photon absorptiometry in osteoporosis and osteomalacia

    SciTech Connect

    Wahner, H.W.

    1987-10-01

    Single- and dual-photon absorptiometric methods have been used in the past to identify populations at risk for bone loss, to define the osteoporotic syndrome in terms of bone mass, and to evaluate treatment regimens to prevent bone loss. Technical improvements have made these procedures available for the nontraumatic measurement of bone mineral in the management of the individual patient suspected of having osteoporosis or other bone loss. This requires a different approach to data interpretation because decisions have to be made on the basis of a single measurement. Osteoporosis and osteomalacia cannot be distinguished by bone mineral measurements because both are characterized by a decrease in content of bone mineral. Bone mineral measurements can be used to assess the risk of fracture and, with it, the severity of bone loss. This allows treatment decisions to be made. Repeated measurements made under well-defined conditions allow estimation of long-term rate of bone loss and monitoring of treatment effect. 38 references.

  8. Single-photon transport through an atomic chain coupled to a one-dimensional nanophotonic waveguide

    NASA Astrophysics Data System (ADS)

    Liao, Zeyang; Zeng, Xiaodong; Zhu, Shi-Yao; Zubairy, M. Suhail

    2015-08-01

    We study the dynamics of a single-photon pulse traveling through a linear atomic chain coupled to a one-dimensional (1D) single mode photonic waveguide. We derive a time-dependent dynamical theory for this collective many-body system which allows us to study the real time evolution of the photon transport and the atomic excitations. Our analytical result is consistent with previous numerical calculations when there is only one atom. For an atomic chain, the collective interaction between the atoms mediated by the waveguide mode can significantly change the dynamics of the system. The reflectivity of a photon can be tuned by changing the ratio of coupling strength and the photon linewidth or by changing the number of atoms in the chain. The reflectivity of a single-photon pulse with finite bandwidth can even approach 100 % . The spectrum of the reflected and transmitted photon can also be significantly different from the single-atom case. Many interesting physical phenomena can occur in this system such as the photonic band-gap effects, quantum entanglement generation, Fano-like interference, and superradiant effects. For engineering, this system may serve as a single-photon frequency filter, single-photon modulation, and may find important applications in quantum information.

  9. Bridging visible and telecom wavelengths with a single-mode broadband photon pair source

    SciTech Connect

    Soeller, C.; Brecht, B.; Mosley, P. J.; Zang, L. Y.; Podlipensky, A.; Joly, N. Y.; Russell, P. St. J.; Silberhorn, C.

    2010-03-15

    We present a spectrally decorrelated photon pair source bridging the visible and telecom wavelength regions. Tailored design and fabrication of a solid-core photonic crystal fiber (PCF) lead to the emission of signal and idler photons into only a single spectral and spatial mode. Thus no narrowband filtering is necessary and the heralded generation of pure photon number states in ultrafast wave packets at telecom wavelengths becomes possible.

  10. Single photon radioluminescence. II. Signal detection and biological applications.

    PubMed Central

    Shahrokh, Z.; Bicknese, S.; Shohet, S. B.; Verkman, A. S.

    1992-01-01

    A quantitative theory for excitation of fluorescent molecules by beta decay electrons is reported in the accompanying manuscript; experimental detection methods and biological applications are reported here. The single photon signals produced by an excited fluorophore (single photon radioluminescence, SPR) provide quantitative information about the distance between radioisotope and fluorophore. Instrumentation was constructed for SPR signal detection. Photons produced in a 0.5-ml sample volume were detected by a cooled photomultiplier and photon counting electronics. To minimize electronic noise and drift for detection of very small SPR signals, a mechanical light chopper was used for gated-signal detection, and a pulse height analyzer for noise rejection. SPR signals of approximately 1 cps were reproducibly measurable. The influence of inner filter effect, sample turbidity, and fluorophore environment (lipid, protein, and carbohydrate) on SPR signals were evaluated experimentally. SPR was then applied to measure lipid exchange kinetics, ligand binding, and membrane transport, and to determine an intermolecular distance in an intact membrane. (a. Lipid exchange kinetics.) Transfer of 12-anthroyloxystearic acid (12-AS) from sonicated lipid vesicles and micelles to vesicles containing 3H-cholesterol was measured from the time course of increasing SPR signal. At 22 degrees C, the half-times for 12-AS transfer from vesicles and micelles were 3.3 and 1.1 min, respectively. (b. Ligand binding.) Binding of 3H-oleic acid to albumin in solution, and 3H-2,2'-dihydro-4,4'-diisothiocyanodisulfonic stilbene (3H-H2DIDS) to band 3 on the erythrocyte membranes were detected by the radioluminescence of the intrinsic tryptophans. The SPR signal from 5 microCi 3H-oleic acid bound to 0.3 mM albumin decreased from 13 +/- 2 cps to 3 +/- 2 cps upon addition of nonradioactive oleic acid, giving 2.7 high affinity oleic acid binding sites per albumin. The SPR signal from 1 microCi 3H-H2DIDS

  11. Single photon radioluminescence. II. Signal detection and biological applications.

    PubMed

    Shahrokh, Z; Bicknese, S; Shohet, S B; Verkman, A S

    1992-11-01

    A quantitative theory for excitation of fluorescent molecules by beta decay electrons is reported in the accompanying manuscript; experimental detection methods and biological applications are reported here. The single photon signals produced by an excited fluorophore (single photon radioluminescence, SPR) provide quantitative information about the distance between radioisotope and fluorophore. Instrumentation was constructed for SPR signal detection. Photons produced in a 0.5-ml sample volume were detected by a cooled photomultiplier and photon counting electronics. To minimize electronic noise and drift for detection of very small SPR signals, a mechanical light chopper was used for gated-signal detection, and a pulse height analyzer for noise rejection. SPR signals of approximately 1 cps were reproducibly measurable. The influence of inner filter effect, sample turbidity, and fluorophore environment (lipid, protein, and carbohydrate) on SPR signals were evaluated experimentally. SPR was then applied to measure lipid exchange kinetics, ligand binding, and membrane transport, and to determine an intermolecular distance in an intact membrane. (a. Lipid exchange kinetics.) Transfer of 12-anthroyloxystearic acid (12-AS) from sonicated lipid vesicles and micelles to vesicles containing 3H-cholesterol was measured from the time course of increasing SPR signal. At 22 degrees C, the half-times for 12-AS transfer from vesicles and micelles were 3.3 and 1.1 min, respectively. (b. Ligand binding.) Binding of 3H-oleic acid to albumin in solution, and 3H-2,2'-dihydro-4,4'-diisothiocyanodisulfonic stilbene (3H-H2DIDS) to band 3 on the erythrocyte membranes were detected by the radioluminescence of the intrinsic tryptophans. The SPR signal from 5 microCi 3H-oleic acid bound to 0.3 mM albumin decreased from 13 +/- 2 cps to 3 +/- 2 cps upon addition of nonradioactive oleic acid, giving 2.7 high affinity oleic acid binding sites per albumin. The SPR signal from 1 microCi 3H-H2DIDS

  12. Efficient single-mode photon-coupling device utilizing a nanofiber tip.

    PubMed

    Chonan, Sho; Kato, Shinya; Aoki, Takao

    2014-01-01

    Single-photon sources are important elements in quantum optics and quantum information science. It is crucial that such sources be able to couple photons emitted from a single quantum emitter to a single propagating mode, preferably to the guided mode of a single-mode optical fiber, with high efficiency. Various photonic devices have been successfully demonstrated to efficiently couple photons from an emitter to a single mode of a cavity or a waveguide. However, efficient coupling of these devices to optical fibers is sometimes challenging. Here we show that up to 38% of photons from an emitter can be directly coupled to a single-mode optical fiber by utilizing the flat tip of a silica nanofiber. With the aid of a metallic mirror, the efficiency can be increased to 76%. The use of a silicon waveguide further increases the efficiency to 87%. This simple device can be applied to various quantum emitters. PMID:24759303

  13. Pseudo-random single photon counting: a high-speed implementation

    PubMed Central

    Zhang, Qiang; Chen, Ling; Chen, Nanguang

    2010-01-01

    Pseudo-random single photon counting (PRSPC) is a new time-resolved optical measurement method which combines the spread spectrum time-resolved method with single photon counting. A pseudo-random bit sequence is used to modulate a continuous wave laser diode, while single photon counting is used to build up the optical signal in response to the modulated excitation. Periodic cross-correlation is performed to obtain the temporal profile of the subject of interest. Compared with conventional time-correlated single photon counting (TCSPC), PRSPC enjoys many advantages such as low cost and high count rate without compromising the sensitivity and time-resolution. In this paper, we report a PRSPC system that can be used for high-speed acquisition of the temporal point spread function of diffuse photons. It can reach a photon count rate as high as 3 Mcps (counts per second). Phantom experiments have been conducted to demonstrate the system performance. PMID:21258444

  14. Dynamically controlling the emission of single excitons in photonic crystal cavities

    PubMed Central

    Pagliano, Francesco; Cho, YongJin; Xia, Tian; van Otten, Frank; Johne, Robert; Fiore, Andrea

    2014-01-01

    Single excitons in semiconductor microcavities represent a solid state and scalable platform for cavity quantum electrodynamics, potentially enabling an interface between flying (photon) and static (exciton) quantum bits in future quantum networks. While both single-photon emission and the strong coupling regime have been demonstrated, further progress has been hampered by the inability to control the coherent evolution of the cavity quantum electrodynamics system in real time, as needed to produce and harness charge–photon entanglement. Here using the ultrafast electrical tuning of the exciton energy in a photonic crystal diode, we demonstrate the dynamic control of the coupling of a single exciton to a photonic crystal cavity mode on a sub-nanosecond timescale, faster than the natural lifetime of the exciton. This opens the way to the control of single-photon waveforms, as needed for quantum interfaces, and to the real-time control of solid-state cavity quantum electrodynamics systems. PMID:25503405

  15. Bias-free true random number generation using superconducting nanowire single-photon detectors

    NASA Astrophysics Data System (ADS)

    He, Yuhao; Zhang, Weijun; Zhou, Hui; You, Lixing; Lv, Chaolin; Zhang, Lu; Liu, Xiaoyu; Wu, Junjie; Chen, Sijing; Ren, Min; Wang, Zhen; Xie, Xiaoming

    2016-08-01

    We demonstrate a bias-free true random number generator (TRNG) based on single photon detection using superconducting nanowire single photon detectors (SNSPDs). By comparing the photon detection signals of two consecutive laser pulses and extracting the random bits by the von Neumann correction method, we achieved a random number generation efficiency of 25% (a generation rate of 3.75 Mbit s‑1 at a system clock rate of 15 MHz). Using a multi-channel superconducting nanowire single photon detector system with controllable pulse signal amplitudes, we detected the single photons with photon number resolution and positional sensitivity, which could further increase the random number generation efficiency. In a three-channel SNSPD system, the random number bit generation efficiency was improved to 75%, corresponding to a generation rate of 7.5 Mbit s‑1 with a 10 MHz system clock rate. All of the generated random numbers successfully passed the statistical test suite.

  16. Dynamically controlling the emission of single excitons in photonic crystal cavities.

    PubMed

    Pagliano, Francesco; Cho, YongJin; Xia, Tian; van Otten, Frank; Johne, Robert; Fiore, Andrea

    2014-01-01

    Single excitons in semiconductor microcavities represent a solid state and scalable platform for cavity quantum electrodynamics, potentially enabling an interface between flying (photon) and static (exciton) quantum bits in future quantum networks. While both single-photon emission and the strong coupling regime have been demonstrated, further progress has been hampered by the inability to control the coherent evolution of the cavity quantum electrodynamics system in real time, as needed to produce and harness charge-photon entanglement. Here using the ultrafast electrical tuning of the exciton energy in a photonic crystal diode, we demonstrate the dynamic control of the coupling of a single exciton to a photonic crystal cavity mode on a sub-nanosecond timescale, faster than the natural lifetime of the exciton. This opens the way to the control of single-photon waveforms, as needed for quantum interfaces, and to the real-time control of solid-state cavity quantum electrodynamics systems. PMID:25503405

  17. A 48-pixel array of Single Photon Avalanche Diodes for multispot Single Molecule analysis

    PubMed Central

    Rech, Ivan; Maccagnani, Piera; Ghioni, Massimo

    2013-01-01

    In this paper we present an array of 48 Single Photon Avalanche Diodes (SPADs) specifically designed for multispot Single Molecule Analysis. The detectors have been arranged in a 12×4 square geometry with a pitch-to-diameter ratio of ten in order to minimize the collection of the light from non-conjugated excitation spots. In order to explore the trade-offs between the detectors’ performance and the optical coupling with the experimental setup, SPADs with an active diameter of 25 and of 50µm have been manufactured. The use of a custom technology, specifically designed for the fabrication of the detectors, allowed us to combine a high photon detection efficiency (peak close to 50% at a wavelength of 550nm) with a low dark count rate compatible with true single molecule detection. In order to allow easy integration into the optical setup for parallel single-molecule analysis, the SPAD array has been incorporated in a compact module containing all the electronics needed for a proper operation of the detectors. PMID:24357913

  18. Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission

    NASA Astrophysics Data System (ADS)

    Sapienza, Luca; Davanço, Marcelo; Badolato, Antonio; Srinivasan, Kartik

    2015-07-01

    Self-assembled, epitaxially grown InAs/GaAs quantum dots (QDs) are promising semiconductor quantum emitters that can be integrated on a chip for a variety of photonic quantum information science applications. However, self-assembled growth results in an essentially random in-plane spatial distribution of QDs, presenting a challenge in creating devices that exploit the strong interaction of single QDs with highly confined optical modes. Here, we present a photoluminescence imaging approach for locating single QDs with respect to alignment features with an average position uncertainty <30 nm (<10 nm when using a solid-immersion lens), which represents an enabling technology for the creation of optimized single QD devices. To that end, we create QD single-photon sources, based on a circular Bragg grating geometry, that simultaneously exhibit high collection efficiency (48%+/-5% into a 0.4 numerical aperture lens, close to the theoretically predicted value of 50%), low multiphoton probability (g(2)(0) <1%), and a significant Purcell enhancement factor (~3).

  19. Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission

    PubMed Central

    Sapienza, Luca; Davanço, Marcelo; Badolato, Antonio; Srinivasan, Kartik

    2015-01-01

    Self-assembled, epitaxially grown InAs/GaAs quantum dots (QDs) are promising semiconductor quantum emitters that can be integrated on a chip for a variety of photonic quantum information science applications. However, self-assembled growth results in an essentially random in-plane spatial distribution of QDs, presenting a challenge in creating devices that exploit the strong interaction of single QDs with highly confined optical modes. Here, we present a photoluminescence imaging approach for locating single QDs with respect to alignment features with an average position uncertainty <30 nm (<10 nm when using a solid-immersion lens), which represents an enabling technology for the creation of optimized single QD devices. To that end, we create QD single-photon sources, based on a circular Bragg grating geometry, that simultaneously exhibit high collection efficiency (48%±5% into a 0.4 numerical aperture lens, close to the theoretically predicted value of 50%), low multiphoton probability (g(2)(0) <1%), and a significant Purcell enhancement factor (≈3). PMID:26211442

  20. Quantum routing of single photons with a cyclic three-level system.

    PubMed

    Zhou, Lan; Yang, Li-Ping; Li, Yong; Sun, C P

    2013-09-01

    We propose an experimentally accessible single-photon routing scheme using a △-type three-level atom embedded in quantum multichannels composed of coupled-resonator waveguides. Via the on-demand classical field being applied to the atom, the router can extract a single photon from the incident channel, and then redirect it into another. The efficient function of the perfect reflection of the single-photon signal in the incident channel is rooted in the coherent resonance and the existence of photonic bound states. PMID:25166667

  1. Waveguide-integrated single- and multi-photon detection at telecom wavelengths using superconducting nanowires

    SciTech Connect

    Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim; Goltsman, Gregory N.; Korneev, Alexander; Pernice, Wolfram H. P.

    2015-04-13

    We investigate single- and multi-photon detection regimes of superconducting nanowire detectors embedded in silicon nitride nanophotonic circuits. At near-infrared wavelengths, simultaneous detection of up to three photons is observed for 120 nm wide nanowires biased far from the critical current, while narrow nanowires below 100 nm provide efficient single photon detection. A theoretical model is proposed to determine the different detection regimes and to calculate the corresponding internal quantum efficiency. The predicted saturation of the internal quantum efficiency in the single photon regime agrees well with plateau behavior observed at high bias currents.

  2. Production of heralded pure single photons from imperfect sources using cross-phase-modulation

    SciTech Connect

    Konrad, Thomas; Nock, Michael; Scherer, Artur; Audretsch, Juergen

    2006-09-15

    Realistic single-photon sources do not generate single photons with certainty. Instead they produce statistical mixtures of photons in Fock states |1> and vacuum (noise). We describe how to eliminate the noise in the output of the sources by means of another noisy source or a coherent state and cross-phase-modulation (XPM). We present a scheme that announces the production of pure single photons and thus eliminates the vacuum contribution. This is done by verifying a XPM-related phase shift with a Mach-Zehnder interferometer.

  3. InGaAs/InAlAs single photon avalanche diode for 1550 nm photons.

    PubMed

    Meng, Xiao; Xie, Shiyu; Zhou, Xinxin; Calandri, Niccolò; Sanzaro, Mirko; Tosi, Alberto; Tan, Chee Hing; Ng, Jo Shien

    2016-03-01

    A single photon avalanche diode (SPAD) with an InGaAs absorption region, and an InAlAs avalanche region was designed and demonstrated to detect 1550 nm wavelength photons. The characterization included leakage current, dark count rate and single photon detection efficiency as functions of temperature from 210 to 294 K. The SPAD exhibited good temperature stability, with breakdown voltage dependence of approximately 45 mV K(-1). Operating at 210 K and in a gated mode, the SPAD achieved a photon detection probability of 26% at 1550 nm with a dark count rate of 1 × 10(8) Hz. The time response of the SPAD showed decreasing timing jitter (full width at half maximum) with increasing overbias voltage, with 70 ps being the smallest timing jitter measured. PMID:27069647

  4. InGaAs/InAlAs single photon avalanche diode for 1550 nm photons

    PubMed Central

    Xie, Shiyu; Zhou, Xinxin; Calandri, Niccolò; Sanzaro, Mirko; Tosi, Alberto; Tan, Chee Hing; Ng, Jo Shien

    2016-01-01

    A single photon avalanche diode (SPAD) with an InGaAs absorption region, and an InAlAs avalanche region was designed and demonstrated to detect 1550 nm wavelength photons. The characterization included leakage current, dark count rate and single photon detection efficiency as functions of temperature from 210 to 294 K. The SPAD exhibited good temperature stability, with breakdown voltage dependence of approximately 45 mV K−1. Operating at 210 K and in a gated mode, the SPAD achieved a photon detection probability of 26% at 1550 nm with a dark count rate of 1 × 108 Hz. The time response of the SPAD showed decreasing timing jitter (full width at half maximum) with increasing overbias voltage, with 70 ps being the smallest timing jitter measured. PMID:27069647

  5. Single spontaneous photon as a coherent beamsplitter for an atomic matter-wave

    SciTech Connect

    Tomkovič, Jiří; Welte, Joachim; Oberthaler, Markus K.; Schreiber, Michael; Kiffner, Martin; Schmiedmayer, Jörg

    2014-12-04

    In free space the spontaneous emission of a single photon destroys motional coherence. Close to a mirror surface the reflection erases the which-path information and the single emitted photon can be regarded as a coherent beam splitter for an atomic matter-wavewhich can be verified by atom interferometry. Our experiment is a realization of the recoiling slit Gedanken experiment by Einstein.

  6. Efficient generation of indistinguishable single photons on-demand at telecom wavelengths

    NASA Astrophysics Data System (ADS)

    Kim, Jehyung; Cai, Tao; Richardson, Christopher; Leavitt, Richard; Waks, Edo

    Highly efficient single photon sources are important building blocks for optical quantum information processing. For practical use and long-distance quantum communication, single photons should have fiber-compatible telecom wavelengths. In addition, most quantum communication applications require high degree of indistinguishability of single photons, such that they exhibit interference on a beam splitter. However, deterministic generation of indistinguishable single photons with high brightness remains a challenging problem in particular at telecom wavelengths. We demonstrate a telecom wavelength source of indistinguishable single photons using an InAs/InP quantum dot in a nanophotonic cavity. To obtain the efficient single quantum dot emission, we employ the higher order mode in L3 photonic crystal cavity that shows a nearly Gaussian transverse mode profile and results in out-coupling efficiency exceeding 46 % and unusual bright single quantum dot emission exceeding 1.5 million counts per second at a detector. We also observe Purcell enhanced spontaneous emission rate as large as 4 and high linear polarization ratio of 0.96 for the coupled dots. Using this source, we generate high purity single photons at 1.3 μm wavelength and demonstrate the indistinguishable nature of the emission using a two-photon interference measurement.

  7. Evaluation of a fast single-photon avalanche photodiode for measurement of early transmitted photons through diffusive media.

    PubMed

    Mu, Ying; Valim, Niksa; Niedre, Mark

    2013-06-15

    We tested the performance of a fast single-photon avalanche photodiode (SPAD) in measurement of early transmitted photons through diffusive media. In combination with a femtosecond titanium:sapphire laser, the overall instrument temporal response time was 59 ps. Using two experimental models, we showed that the SPAD allowed measurement of photon-density sensitivity functions that were approximately 65% narrower than the ungated continuous wave case at very early times. This exceeds the performance that we have previously achieved with photomultiplier-tube-based systems and approaches the theoretical maximum predicted by time-resolved Monte Carlo simulations. PMID:23938989

  8. Low-noise low-jitter 32-pixels CMOS single-photon avalanche diodes array for single-photon counting from 300 nm to 900 nm.

    PubMed

    Scarcella, Carmelo; Tosi, Alberto; Villa, Federica; Tisa, Simone; Zappa, Franco

    2013-12-01

    We developed a single-photon counting multichannel detection system, based on a monolithic linear array of 32 CMOS SPADs (Complementary Metal-Oxide-Semiconductor Single-Photon Avalanche Diodes). All channels achieve a timing resolution of 100 ps (full-width at half maximum) and a photon detection efficiency of 50% at 400 nm. Dark count rate is very low even at room temperature, being about 125 counts/s for 50 μm active area diameter SPADs. Detection performance and microelectronic compactness of this CMOS SPAD array make it the best candidate for ultra-compact time-resolved spectrometers with single-photon sensitivity from 300 nm to 900 nm. PMID:24387425

  9. Low-noise low-jitter 32-pixels CMOS single-photon avalanche diodes array for single-photon counting from 300 nm to 900 nm

    SciTech Connect

    Scarcella, Carmelo; Tosi, Alberto Villa, Federica; Tisa, Simone; Zappa, Franco

    2013-12-15

    We developed a single-photon counting multichannel detection system, based on a monolithic linear array of 32 CMOS SPADs (Complementary Metal-Oxide-Semiconductor Single-Photon Avalanche Diodes). All channels achieve a timing resolution of 100 ps (full-width at half maximum) and a photon detection efficiency of 50% at 400 nm. Dark count rate is very low even at room temperature, being about 125 counts/s for 50 μm active area diameter SPADs. Detection performance and microelectronic compactness of this CMOS SPAD array make it the best candidate for ultra-compact time-resolved spectrometers with single-photon sensitivity from 300 nm to 900 nm.

  10. Large conditional single-photon cross-phase modulation.

    PubMed

    Beck, Kristin M; Hosseini, Mahdi; Duan, Yiheng; Vuletić, Vladan

    2016-08-30

    Deterministic optical quantum logic requires a nonlinear quantum process that alters the phase of a quantum optical state by π through interaction with only one photon. Here, we demonstrate a large conditional cross-phase modulation between a signal field, stored inside an atomic quantum memory, and a control photon that traverses a high-finesse optical cavity containing the atomic memory. This approach avoids fundamental limitations associated with multimode effects for traveling optical photons. We measure a conditional cross-phase shift of [Formula: see text] (and up to [Formula: see text] by postselection on photons that remain in the system longer than average) between the retrieved signal and control photons, and confirm deterministic entanglement between the signal and control modes by extracting a positive concurrence. By upgrading to a state-of-the-art cavity, our system can reach a coherent phase shift of π at low loss, enabling deterministic and universal photonic quantum logic. PMID:27519798

  11. Non-Geiger mode single photon detector with multiple amplification and gain control mechanisms

    SciTech Connect

    Nawar Rahman, Samia Hall, David; Lo, Yu-Hwa

    2014-05-07

    A new type of single photon detector, Multiple Amplification Gain with Internal Control (MAGIC), is proposed and analyzed using Monte Carlo simulations based on a physical model of the device. The MAGIC detector has two coupled amplification mechanisms, avalanche multiplication and bipolar gain, and the net gain is regulated by a built-in feedback mechanism. Compared to conventional Geiger mode single photon avalanche detectors (SPADs), the MAGIC detector produces a much greater single photon detection efficiency of nearly 100%, low bit-error-ratio for single photon signals, and a large dynamic range. All these properties are highly desirable for applications that require single photon sensitivity and are absent for conventional Geiger-mode SPADs.

  12. Experimental single-photon exchange along a space link of 7000 km

    NASA Astrophysics Data System (ADS)

    Dequal, Daniele; Vallone, Giuseppe; Bacco, Davide; Gaiarin, Simone; Luceri, Vincenza; Bianco, Giuseppe; Villoresi, Paolo

    2016-01-01

    Extending the single-photon transmission distance is a basic requirement for the implementation of quantum communication on a global scale. In this work we report the single-photon exchange from a medium Earth orbit satellite (MEO) at more than 7000 km of slant distance to the ground station at the Matera Laser Ranging Observatory. The single-photon transmitter was realized by exploiting the corner cube retroreflectors mounted on the LAGEOS-2 satellite. Long duration of data collection is possible with such altitude, up to 43 min in a single passage. The mean number of photons per pulse (μsat) has been limited to 1 for 200 s, resulting in an average detection rate of 3.0 counts/s and a signal-to-noise ratio of 1.5. The feasibility of single-photon exchange from MEO satellites paves the way to tests of quantum mechanics in moving frames and to global quantum Information.

  13. Multiple intrinsically identical single-photon emitters in the solid state.

    PubMed

    Rogers, L J; Jahnke, K D; Teraji, T; Marseglia, L; Müller, C; Naydenov, B; Schauffert, H; Kranz, C; Isoya, J; McGuinness, L P; Jelezko, F

    2014-01-01

    Emitters of indistinguishable single photons are crucial for the growing field of quantum technologies. To realize scalability and increase the complexity of quantum optics technologies, multiple independent yet identical single-photon emitters are required. However, typical solid-state single-photon sources are inherently dissimilar, necessitating the use of electrical feedback or optical cavities to improve spectral overlap between distinct emitters. Here we demonstrate bright silicon vacancy (SiV(-)) centres in low-strain bulk diamond, which show spectral overlap of up to 91% and nearly transform-limited excitation linewidths. This is the first time that distinct single-photon emitters in the solid state have shown intrinsically identical spectral properties. Our results have impact on the application of single-photon sources for quantum optics and cryptography. PMID:25162729

  14. Up-conversion single-photon detector using multi-wavelength sampling techniques.

    PubMed

    Ma, Lijun; Bienfang, Joshua C; Slattery, Oliver; Tang, Xiao

    2011-03-14

    The maximum achievable data-rate of a quantum communication system can be critically limited by the efficiency and temporal resolution of the system's single-photon detectors. Frequency up-conversion technology can be used to increase detection efficiency for IR photons. In this paper we describe a scheme to improve the temporal resolution of an up-conversion single-photon detector using multi-wavelength optical-sampling techniques, allowing for increased transmission rates in single-photon communications systems. We experimentally demonstrate our approach with an up-conversion detector using two spectrally and temporally distinct pump pulses, and show that it allows for high-fidelity single-photon detection at twice the rate supported by a conventional single-pump up-conversion detector. We also discuss the limiting factors of this approach and identify important performance-limiting trade offs. PMID:21445185

  15. Photophysics of chromium-related diamond single-photon emitters

    SciTech Connect

    Aharonovich, I.; Castelletto, S.; Simpson, D. A.; Greentree, A. D.; Prawer, S.

    2010-04-15

    A detailed study of the photophysical properties of several chromium-related color centers produced within chemical vapor deposition diamond is presented. These emitters show narrow luminescence lines in the range of 740-770 nm. Single-photon emission was verified with continuous and pulsed excitation with detected emission rates at saturation in the range of (2-3) x 10{sup 6} counts/s, while direct lifetime measurements reveal excited state lifetimes for the distinct centers ranging 1-14 ns. In addition, a number of quantum emitters demonstrate two-level behavior with no bunching present in the second-order correlation function. The three-level systems revealed typically photoluminescence lines with width half-maximum of {approx}4 nm while the two-level emitters have full width half-maximum of {approx}10 nm at room temperature. In addition, the quantum efficiency of the two-level system was measured to be four times higher than that of the three-level system.

  16. Single photon emission tomography imaging in parkinsonian disorders: a review.

    PubMed

    Acton, P D; Mozley, P D

    2000-01-01

    Parkinsonian symptoms are associated with a number of neurodegenerative disorders, such as Parkinson's disease, multiple system atrophy and progressive supranuclear palsy. Pathological evidence has shown clearly that these disorders are associated with a loss of neurons, particularly in the nigrostriatal dopaminergic pathway. Positron emission tomography (PET) and single photon emission tomography (SPECT) now are able to visualise and quantify changes in cerebral blood flow, glucose metabolism, and dopaminergic function produced by parkinsonian disorders. Both PET and SPECT have become important tools in the differential diagnosis of these diseases, and may have sufficient sensitivity to detect neuronal changes before the onset of clinical symptoms. Imaging is now being utilised to elucidate the genetic contribution to Parkinson's disease, and in longitudinal studies to assess the efficacy and mode of action of neuroprotective drug and surgical treatments. This review summarises recent applications of SPECT imaging in the study of parkinsonian disorders, with particular reference to the increasing role it is playing in the understanding, diagnosis and management of these diseases. PMID:11455039

  17. The atomic coilgun and single-photon cooling

    NASA Astrophysics Data System (ADS)

    Libson, Adam; Bannerman, Stephen Travis; Clark, Robert J.; Mazur, Thomas R.; Raizen, Mark G.

    As the simplest atom, hydrogen has a unique role as a testing ground of fundamental physics. Precision measurements of the hydrogen atomic structure provide stringent tests of current theory, while tritium is an excellent candidate for studies of β-decay and possible measurement of the neutrino rest mass. Furthermore, precision measurement of antihydrogen would allow for tests of fundamental symmetries. Methods demonstrated in our lab provide an avenue by which hydrogen isotopes can be trapped and cooled to near the recoil limit. The atomic coilgun, which we have demonstrated with metastable neon and molecular oxygen, provides a general method of stopping a supersonic beam of any paramagnetic species. This tool provides a method by which hydrogen and its isotopes can be magnetically trapped at around 100 mK using a room temperature apparatus. Another tool developed in our laboratory, single-photon cooling, allows further cooling of a trapped sample to near the recoil limit. This cooling method has already been demonstrated on a trapped sample of rubidium. We report on the progress of implementing these methods to trap and cool hydrogen isotopes, and on the prospects for using cold trapped hydrogen for precision measurements.

  18. Realizing quantum advantage without entanglement in single-photon states

    NASA Astrophysics Data System (ADS)

    Maldonado Trapp, Alejandra; Solano, Pablo; Hu, Anzi; Clark, Charles W.

    2016-05-01

    Quantum discord expresses quantum correlations beyond those associated with entanglement. Although it has been extensively studied theoretically, quantum discord has yet to become a standard tool in experimental studies of correlation. We propose a class of experiments in which quantum correlations are present in the absence of entanglement, and are best understood in terms of quantum discord.. These utilize X-states of two qubits, which correspond to the polarization and the optical path of a single photon within a Mach-Zehnder interferometer. We show how to produce states with diverse measures of discord and entanglement, including the case of discord without entanglement. With these states we show how a classical random variable K can be encoded by Alice and decoded by Bob. Using our previous results we analytically study the correlations between the spin and path qubits and its relation with the information about K that can be decoded by Bob using local measurements with or without two-qubit gate operations.

  19. Single photon emission computed tomography-guided Cerenkov luminescence tomography

    NASA Astrophysics Data System (ADS)

    Hu, Zhenhua; Chen, Xueli; Liang, Jimin; Qu, Xiaochao; Chen, Duofang; Yang, Weidong; Wang, Jing; Cao, Feng; Tian, Jie

    2012-07-01

    Cerenkov luminescence tomography (CLT) has become a valuable tool for preclinical imaging because of its ability of reconstructing the three-dimensional distribution and activity of the radiopharmaceuticals. However, it is still far from a mature technology and suffers from relatively low spatial resolution due to the ill-posed inverse problem for the tomographic reconstruction. In this paper, we presented a single photon emission computed tomography (SPECT)-guided reconstruction method for CLT, in which a priori information of the permissible source region (PSR) from SPECT imaging results was incorporated to effectively reduce the ill-posedness of the inverse reconstruction problem. The performance of the method was first validated with the experimental reconstruction of an adult athymic nude mouse implanted with a Na131I radioactive source and an adult athymic nude mouse received an intravenous tail injection of Na131I. A tissue-mimic phantom based experiment was then conducted to illustrate the ability of the proposed method in resolving double sources. Compared with the traditional PSR strategy in which the PSR was determined by the surface flux distribution, the proposed method obtained much more accurate and encouraging localization and resolution results. Preliminary results showed that the proposed SPECT-guided reconstruction method was insensitive to the regularization methods and ignored the heterogeneity of tissues which can avoid the segmentation procedure of the organs.

  20. Brain single photon emission computed tomography in neonates

    SciTech Connect

    Denays, R.; Van Pachterbeke, T.; Tondeur, M.; Spehl, M.; Toppet, V.; Ham, H.; Piepsz, A.; Rubinstein, M.; Nol, P.H.; Haumont, D. )

    1989-08-01

    This study was designed to rate the clinical value of ({sup 123}I)iodoamphetamine (IMP) or ({sup 99m}Tc) hexamethyl propylene amine oxyme (HM-PAO) brain single photon emission computed tomography (SPECT) in neonates, especially in those likely to develop cerebral palsy. The results showed that SPECT abnormalities were congruent in most cases with structural lesions demonstrated by ultrasonography. However, mild bilateral ventricular dilatation and bilateral subependymal porencephalic cysts diagnosed by ultrasound were not associated with an abnormal SPECT finding. In contrast, some cortical periventricular and sylvian lesions and all the parasagittal lesions well visualized in SPECT studies were not diagnosed by ultrasound scans. In neonates with subependymal and/or intraventricular hemorrhage the existence of a parenchymal abnormality was only diagnosed by SPECT. These results indicate that ({sup 123}I)IMP or ({sup 99m}Tc)HM-PAO brain SPECT shows a potential clinical value as the neurodevelopmental outcome is clearly related to the site, the extent, and the number of cerebral lesions. Long-term clinical follow-up is, however, mandatory in order to define which SPECT abnormality is associated with neurologic deficit.

  1. Monitoring cellular mechanosensing using time-correlated single photon counting

    NASA Astrophysics Data System (ADS)

    Tabouillot, Tristan; Gullapalli, Ramachandra; Butler, Peter J.

    2006-10-01

    Endothelial cells (ECs) convert mechanical stimuli into chemical signaling pathways to regulate their functions and properties. It is hypothesized that perturbation of cellular structures by force is accompanied by changes in molecular dynamics. In order to address these fundamental issues in mechanosensation and transduction, we have developed a hybrid multimodal microscopy - time-correlated single photon counting (TCSPC) spectroscopy system intended to determine time- and position dependent mechanically-induced changes in the dynamics of molecules in live cells as determined from fluorescence lifetimes and autocorrelation analysis (fluorescence correlation spectroscopy). Colocalization of cell-structures and mechanically-induced changes in molecular dynamics can be done in post-processing by comparing TCSPC data with 3-D models generated from total internal reflection fluorescence (TIRF), differential interference contrast (DIC), epifluorescence, and deconvolution. We present control experiments in which the precise location of the apical cell membrane with respect to a confocal probe is assessed using information obtainable only from TCSPC. Such positional accuracy of TCSPC measurements is essential to understanding the role of the membrane in mechanotransduction. We predict that TCSPC will become a useful method to obtain high temporal and spatial resolution information on localized mechanical phenomena in living endothelial cells. Such insight into mechanotransduction phenomenon may uncover the origins of mechanically-related diseases such as atherosclerosis.

  2. Optical π phase shift created with a single-photon pulse

    PubMed Central

    Tiarks, Daniel; Schmidt, Steffen; Rempe, Gerhard; Dürr, Stephan

    2016-01-01

    A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the detection of a retrieved photon from the first pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing. PMID:27386511

  3. Optical π phase shift created with a single-photon pulse.

    PubMed

    Tiarks, Daniel; Schmidt, Steffen; Rempe, Gerhard; Dürr, Stephan

    2016-04-01

    A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the detection of a retrieved photon from the first pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing. PMID:27386511

  4. Cavity-Free Scheme for Nondestructive Detection of a Single Optical Photon.

    PubMed

    Xia, Keyu; Johnsson, Mattias; Knight, Peter L; Twamley, Jason

    2016-01-15

    Detecting a single photon without absorbing it is a long-standing challenge in quantum optics. All experiments demonstrating the nondestructive detection of a photon make use of a high quality cavity. We present a cavity-free scheme for nondestructive single-photon detection. By pumping a nonlinear medium we implement an interfield Rabi oscillation which leads to a ∼π phase shift on a weak probe coherent laser field in the presence of a single signal photon without destroying the signal photon. Our cavity-free scheme operates with a fast intrinsic time scale in comparison with similar cavity-based schemes. We implement a full real-space multimode numerical analysis of the interacting photonic modes and confirm the validity of our nondestructive scheme in the multimode case. PMID:26824538

  5. On-chip interference of single photons from an embedded quantum dot and an external laser

    NASA Astrophysics Data System (ADS)

    Prtljaga, N.; Bentham, C.; O'Hara, J.; Royall, B.; Clarke, E.; Wilson, L. R.; Skolnick, M. S.; Fox, A. M.

    2016-06-01

    In this work, we demonstrate the on-chip two-photon interference between single photons emitted by a single self-assembled InGaAs quantum dot and an external laser. The quantum dot is embedded within one arm of an air-clad directional coupler which acts as a beam-splitter for incoming light. Photons originating from an attenuated external laser are coupled to the second arm of the beam-splitter and then combined with the quantum dot photons, giving rise to two-photon quantum interference between dissimilar sources. We verify the occurrence of on-chip Hong-Ou-Mandel interference by cross-correlating the optical signal from the separate output ports of the directional coupler. This experimental approach allows us to use a classical light source (laser) to assess in a single step the overall device performance in the quantum regime and probe quantum dot photon indistinguishability on application realistic time scales.

  6. τ-SPAD: a new red sensitive single-photon counting module

    NASA Astrophysics Data System (ADS)

    Kell, Gerald; Bülter, Andreas; Wahl, Michael; Erdmann, Rainer

    2011-05-01

    Single Photon Avalanche Diodes (SPADs) are valuable detectors in numerous photon counting applications in the fields of quantum physics, quantum communication, astronomy, metrology and biomedical analytics. They typically feature a much higher photon detection efficiency than photomultiplier tubes, most importantly in the red to near-infrared range of the spectrum. Very often SPADs are combined with Time-Correlated Single Photon Counting (TCSPC) electronics for time-resolved data acquisition and the temporal resolution ("jitter") of a SPAD is therefore one of the key parameters for selecting a detector. We show technical data and first application results from a new type of red sensitive single photon counting module ("τ-SPAD"), which is targeted at timing applications, most prominently in the area of Single Molecule Spectroscopy (SMS). The τ-SPAD photon counting module combines Laser Components' ultra-low noise VLoK silicon avalanche photodiode with specially developed quenching and readout electronics from PicoQuant. It features an extremely high photon detection efficiency of 75% at 670 nm and can be used to detect single photons over the 400 nm to 1100 nm wavelength range. The timing jitter of the output of the τ-SPAD can be as low as 350 ps, making it suitable for time-resolved fluorescence detection applications. First photon coincidence correlation measurements also show that the typical breakdown flash of SPADs is of comparably low intensity for these new SPADs.

  7. Spectral overlap in direct measurements of displaced single-photon states

    NASA Astrophysics Data System (ADS)

    Laiho, K.; Avenhaus, M.; Cassemiro, K. N.; Silberhorn, C.

    2011-10-01

    Many sophisticated quantum states of light display non-classical, characteristic oscillations in their photon statistics altering with respect to the applied displacement. In order to detect these oscillations the mode matching between the studied state and the displacement field plays a crucial role. Only recently the developments in the photon counting techniques have allowed the direct measurements of the photon-number distributions of quantum states. We investigate the properties of displaced single photons by applying time-multiplexed detection of photon statistics and quantify the value of the mode overlap.

  8. ASP: a new PEP experiment to measure single photons

    SciTech Connect

    Hollebeek, R.

    1984-05-01

    The design and construction of a new experiment for PEP designed to measure the flux of low energy photons unaccompanied by any additional photons, or charged tracks is described. The device consists of arrays of extruded lead glass bars and PWC's in the central region with lead-scintillator shower counters, drift chambers and PWC's in the forward regions. 9 references.

  9. Single photon counter for digital x-ray mammography tomosynthesis

    SciTech Connect

    Goldan, Amir H.; Karim, Karim S.; Rowlands, John A.

    2006-05-15

    Photon counting is an emerging detection technique that is promising for mammography tomosynthesis imagers. In photon counting systems, the value of each image pixel is equal to the number of photons that interact with the detector. In this research, we introduce the design and implementation of a low noise, photon counting pixel for digital mammography tomosynthesis in 0.18 {mu}m crystalline silicon complementary metal-oxide semiconductor technology. The design comprises of a low noise, charge-integrating amplifier, a low offset voltage comparator, a decision-making unit, a mode selector, and a pseudorandom counter. Theoretical calculations and simulation results of linearity, gain, and noise of the photon counting pixel are presented.

  10. Large conditional single-photon cross-phase modulation

    NASA Astrophysics Data System (ADS)

    Beck, Kristin; Hosseini, Mahdi; Duan, Yiheng; Vuletic, Vladan

    2016-05-01

    Deterministic optical quantum logic requires a nonlinear quantum process that alters the phase of a quantum optical state by π through interaction with only one photon. Here, we demonstrate a large conditional cross-phase modulation between a signal field, stored inside an atomic quantum memory, and a control photon that traverses a high-finesse optical cavity containing the atomic memory. This approach avoids fundamental limitations associated with multimode effects for traveling optical photons. We measure a conditional cross-phase shift of up to π / 3 between the retrieved signal and control photons, and confirm deterministic entanglement between the signal and control modes by extracting a positive concurrence. With a moderate improvement in cavity finesse, our system can reach a coherent phase shift of p at low loss, enabling deterministic and universal photonic quantum logic. Preprint: arXiv:1512.02166 [quant-ph

  11. Time-reversal-symmetric single-photon wave packets for free-space quantum communication.

    PubMed

    Trautmann, N; Alber, G; Agarwal, G S; Leuchs, G

    2015-05-01

    Readout and retrieval processes are proposed for efficient, high-fidelity quantum state transfer between a matter qubit, encoded in the level structure of a single atom or ion, and a photonic qubit, encoded in a time-reversal-symmetric single-photon wave packet. They are based on controlling spontaneous photon emission and absorption of a matter qubit on demand in free space by stimulated Raman adiabatic passage. As these processes do not involve mode selection by high-finesse cavities or photon transport through optical fibers, they offer interesting perspectives as basic building blocks for free-space quantum-communication protocols. PMID:25978231

  12. Time-Reversal-Symmetric Single-Photon Wave Packets for Free-Space Quantum Communication

    NASA Astrophysics Data System (ADS)

    Trautmann, N.; Alber, G.; Agarwal, G. S.; Leuchs, G.

    2015-05-01

    Readout and retrieval processes are proposed for efficient, high-fidelity quantum state transfer between a matter qubit, encoded in the level structure of a single atom or ion, and a photonic qubit, encoded in a time-reversal-symmetric single-photon wave packet. They are based on controlling spontaneous photon emission and absorption of a matter qubit on demand in free space by stimulated Raman adiabatic passage. As these processes do not involve mode selection by high-finesse cavities or photon transport through optical fibers, they offer interesting perspectives as basic building blocks for free-space quantum-communication protocols.

  13. Temporal Purity and Quantum Interference of Single Photons from Two Independent Cold Atomic Ensembles

    NASA Astrophysics Data System (ADS)

    Qian, Peng; Gu, Zhenjie; Cao, Rong; Wen, Rong; Ou, Z. Y.; Chen, J. F.; Zhang, Weiping

    2016-07-01

    The temporal purity of single photons is crucial to the indistinguishability of independent photon sources for the fundamental study of the quantum nature of light and the development of photonic technologies. Currently, the technique for single photons heralded from time-frequency entangled biphotons created in nonlinear crystals does not guarantee the temporal-quantum purity, except using spectral filtering. Nevertheless, an entirely different situation is anticipated for narrow-band biphotons with a coherence time far longer than the time resolution of a single-photon detector. Here we demonstrate temporally pure single photons with a coherence time of 100 ns, directly heralded from the time-frequency entangled biphotons generated by spontaneous four-wave mixing in cold atomic ensembles, without any supplemented filters or cavities. A near-perfect purity and indistinguishability are both verified through Hong-Ou-Mandel quantum interference using single photons from two independent cold atomic ensembles. The time-frequency entanglement provides a route to manipulate the pure temporal state of the single-photon source.

  14. Temporal Purity and Quantum Interference of Single Photons from Two Independent Cold Atomic Ensembles.

    PubMed

    Qian, Peng; Gu, Zhenjie; Cao, Rong; Wen, Rong; Ou, Z Y; Chen, J F; Zhang, Weiping

    2016-07-01

    The temporal purity of single photons is crucial to the indistinguishability of independent photon sources for the fundamental study of the quantum nature of light and the development of photonic technologies. Currently, the technique for single photons heralded from time-frequency entangled biphotons created in nonlinear crystals does not guarantee the temporal-quantum purity, except using spectral filtering. Nevertheless, an entirely different situation is anticipated for narrow-band biphotons with a coherence time far longer than the time resolution of a single-photon detector. Here we demonstrate temporally pure single photons with a coherence time of 100 ns, directly heralded from the time-frequency entangled biphotons generated by spontaneous four-wave mixing in cold atomic ensembles, without any supplemented filters or cavities. A near-perfect purity and indistinguishability are both verified through Hong-Ou-Mandel quantum interference using single photons from two independent cold atomic ensembles. The time-frequency entanglement provides a route to manipulate the pure temporal state of the single-photon source. PMID:27419568

  15. Single-photon emission from cubic GaN quantum dots

    SciTech Connect

    Kako, Satoshi; Holmes, Mark; Sergent, Sylvain; Bürger, Matthias; As, Donat J.; Arakawa, Yasuhiko

    2014-01-06

    We report the demonstration of single-photon emission from cubic GaN/AlN quantum dots grown by molecular beam epitaxy. We have observed spectrally clean and isolated emission peaks from these quantum dots. Clear single-photon emission was detected by analyzing one such peak at 4 K. The estimated g{sup (2)}[0] value is 0.25, which becomes 0.05 when corrected for background and detector dark counts. We have also observed the single-photon nature of the emission up to 100 K (g{sup (2)}[0] = 0.47). These results indicate that cubic GaN quantum dots are possible candidates for high-temperature operating UV single-photon sources with the possibility of integration into photonic nanostructures.

  16. Wiring up pre-characterized single-photon emitters by laser lithography

    PubMed Central

    Shi, Q.; Sontheimer, B.; Nikolay, N.; Schell, A. W.; Fischer, J.; Naber, A.; Benson, O.; Wegener, M.

    2016-01-01

    Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time. PMID:27507165

  17. Wiring up pre-characterized single-photon emitters by laser lithography

    NASA Astrophysics Data System (ADS)

    Shi, Q.; Sontheimer, B.; Nikolay, N.; Schell, A. W.; Fischer, J.; Naber, A.; Benson, O.; Wegener, M.

    2016-08-01

    Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time.

  18. Optimizing single-nanoparticle two-photon microscopy by in situ adaptive control of femtosecond pulses

    NASA Astrophysics Data System (ADS)

    Li, Donghai; Deng, Yongkai; Chu, Saisai; Jiang, Hongbing; Wang, Shufeng; Gong, Qihuang

    2016-07-01

    Single-nanoparticle two-photon microscopy shows great application potential in super-resolution cell imaging. Here, we report in situ adaptive optimization of single-nanoparticle two-photon luminescence signals by phase and polarization modulations of broadband laser pulses. For polarization-independent quantum dots, phase-only optimization was carried out to compensate the phase dispersion at the focus of the objective. Enhancement of the two-photon excitation fluorescence intensity under dispersion-compensated femtosecond pulses was achieved. For polarization-dependent single gold nanorod, in situ polarization optimization resulted in further enhancement of two-photon photoluminescence intensity than phase-only optimization. The application of in situ adaptive control of femtosecond pulse provides a way for object-oriented optimization of single-nanoparticle two-photon microscopy for its future applications.

  19. Wiring up pre-characterized single-photon emitters by laser lithography.

    PubMed

    Shi, Q; Sontheimer, B; Nikolay, N; Schell, A W; Fischer, J; Naber, A; Benson, O; Wegener, M

    2016-01-01

    Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time. PMID:27507165

  20. Broadband single-polarization single-mode photonic crystal fibers with three different background materials.

    PubMed

    Li, Hui; Li, Shu-guang; Li, Jian-She; Zhang, Wan; An, Guo-Wen

    2015-04-01

    A modified structure of single-polarization single-mode (SPSM) photonic crystal fiber (PCF) with different background materials is presented and analyzed by using the full-vector finite-element method. Simulation results confirmed that the proposed PCF can realize low-loss SPSM on three wavebands with the same structure and different background materials. The wavebands are 1.46-1.60 μm for silica-based fiber, 1.97-2.3 μm for lead silicate glass fiber, and 3.16-3.58 μm for chalcogenide glass fiber. For three PCFs with different background materials, only the slow-axis mode exists and the confinement loss is less than 100 dB/m in the SPSM wavebands. PMID:25967199

  1. Radiopharmaceuticals for single-photon emission computed tomography brain imaging.

    PubMed

    Kung, Hank F; Kung, Mei-Ping; Choi, Seok Rye

    2003-01-01

    In the past 10 years, significant progress on the development of new brain-imaging agents for single-photon emission computed tomography has been made. Most of the new radiopharmaceuticals are designed to bind specific neurotransmitter receptor or transporter sites in the central nervous system. Most of the site-specific brain radiopharmaceuticals are labeled with (123)I. Results from imaging of benzodiazepine (gamma-aminobutyric acid) receptors by [(123)I]iomazenil are useful in identifying epileptic seizure foci and changes of this receptor in psychiatric disorders. Imaging of dopamine D2/D3 receptors ([(123)I]iodobenzamide and [(123)I]epidepride) and transporters [(123)I]CIT (2-beta-carboxymethoxy-3-beta(4-iodophenyl)tropane) and [(123)I]FP-beta-CIT (N-propyl-2-beta-carboxymethoxy-3-beta(4-iodophenyl)-nortropane has proven to be a simple but powerful tool for differential diagnosis of Parkinson's and other neurodegenerative diseases. A (99m)Tc-labeled agent, [(99m)Tc]TRODAT (technetium, 2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo [3,2,1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino] ethanethiolato(3-)]oxo-[1R-(exo-exo)]-), for imaging dopamine transporters in the brain has been successfully applied in the diagnosis of Parkinson's disease. Despite the fact that (123)I radiopharmaceuticals have been widely used in Japan and in Europe, clinical application of (123)I-labeled brain radiopharmaceuticals in the United States is limited because of the difficulties in supplying such agents. Development of (99m)Tc agents will likely extend the application of site-specific brain radiopharmaceuticals for routine applications in aiding the diagnosis and monitoring treatments of various neurologic and psychiatric disorders. PMID:12605353

  2. Site-controlled InGaN/GaN single-photon-emitting diode

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Teng, Chu-Hsiang; Ku, Pei-Cheng; Deng, Hui

    2016-04-01

    We report single-photon emission from electrically driven site-controlled InGaN/GaN quantum dots. The device is fabricated from a planar light-emitting diode structure containing a single InGaN quantum well, using a top-down approach. The location, dimension, and height of each single-photon-emitting diode are controlled lithographically, providing great flexibility for chip-scale integration.

  3. Single photon counting for space based quantum experiments

    NASA Astrophysics Data System (ADS)

    Chandrasekara, R.; Tang, Z. K.; Tan, Y. C.; Cheng, C.; Wildfeuer, C.; Ling, A.

    2015-05-01

    We present a software based control system for Geiger-mode avalanche photodiodes (GM-APDs) that enables constant photon detection efficiency irrespective of the diode's junction temperature. Furthermore, we demonstrate that this control system enables passively quenched GM-APDs to double the rate of photon detection events before saturation compared to the standard control method that fixes the junction temperature and applied bias voltage. We present data demonstrating the robustness of the GM-APD control system when tested in near-space conditions using a correlated photon pair source carried by a weather balloon to an altitude of 35.5 km.

  4. Room-temperature single-photon generation from solitary dopants of carbon nanotubes.

    PubMed

    Ma, Xuedan; Hartmann, Nicolai F; Baldwin, Jon K S; Doorn, Stephen K; Htoon, Han

    2015-08-01

    On-demand single-photon sources capable of operating at room temperature and the telecom wavelength range of 1,300-1,500 nm hold the key to the realization of novel technologies that span from sub-diffraction imaging to quantum key distribution and photonic quantum information processing. Here, we show that incorporation of undoped (6,5) single-walled carbon nanotubes into a SiO2 matrix can lead to the creation of solitary oxygen dopant states capable of fluctuation-free, room-temperature single-photon emission in the 1,100-1,300 nm wavelength range. We investigated the effects of temperature on photoluminescence emission efficiencies, fluctuations and decay dynamics of the dopant states and determined the conditions most suitable for the observation of single-photon emission. This emission can in principle be extended to 1,500 nm by doping of smaller-bandgap single-walled carbon nanotubes. This easy tunability presents a distinct advantage over existing defect centre single-photon emitters (for example, diamond defect centres). Our SiO2-encapsulated sample also presents exciting opportunities to apply Si/SiO2-based micro/nano-device fabrication techniques in the development of electrically driven single-photon sources and integration of these sources into quantum photonic devices and networks. PMID:26167766

  5. Electrically driven single photon emission from a CdSe/ZnSSe single quantum dot at 200 K

    SciTech Connect

    Quitsch, Wolf; Kümmell, Tilmar; Bacher, Gerd; Gust, Arne; Kruse, Carsten; Hommel, Detlef

    2014-09-01

    High temperature operation of an electrically driven single photon emitter based on a single epitaxial quantum dot is reported. CdSe/ZnSSe/MgS quantum dots are embedded into a p-i-n diode architecture providing almost background free excitonic and biexcitonic electroluminescence from individual quantum dots through apertures in the top contacts. Clear antibunching with g{sup 2}(τ = 0) = 0.28 ± 0.20 can be tracked up to T = 200 K, representing the highest temperature for electrically triggered single photon emission from a single quantum dot device.

  6. Optical Pi Phase Shift Created with a Single-Photon Pulse

    NASA Astrophysics Data System (ADS)

    Schmidt, Steffen; Tiarks, Daniel; Dürr, Stephan; Rempe, Gerhard

    2016-05-01

    A deterministic photon-photon quantum-logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of pi onto another light field. Here we experimentally demonstrate the generation of such a pi phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a pi phase shift for a second light pulse which propagates through the medium. This demonstrates the crucial step towards a photon-photon gate and offers a variety of applications in the field of quantum information processing.

  7. Developing a Parametric Downconversion Apparatus for Single-Photon Experiments in Quantum Optics

    NASA Astrophysics Data System (ADS)

    Diiorio, Stephen

    2015-05-01

    We report our progress toward developing a parametric downconversion apparatus for studying single-photon quantum optics in undergraduate laboratory classes, following the model of Galvez et al.. We pump a beta barium borate (BBO) crystal with a 405 nm diode laser to produce correlated pairs of single-photons that we detect using avalanche photodiodes (APD). We can conduct coincidence and anti-coincidence counts and a measurement of the degree of second-order coherence with the apparatus, and we expect to report on single- and bi-photon interferometry experiments.

  8. Single-Photon Scattering Grating in a Waveguide-Cavity System

    NASA Astrophysics Data System (ADS)

    Huang, Jin-Song; Li, Yan-Ling; Xu, Zhong-Hui; Huang, You-wen

    2016-09-01

    We investigate single-photon scattering grating in a one-dimensional waveguide coupled to a cavity embedded with a driven Λ-type three-level atom. The single-photon reflection amplitude and transmission amplitude in the waveguide are obtained via a real-space approach, respectively. By spatially modulating a classical control field to drive the three-level emitter, alternating regions of high reflection and absorption as well as high transmission and absorption of the single photon are generated in both directions of the waveguide, which acts as a kind of scattering grating. The proposed scheme may have the potential for the design of chip-integrated grating.

  9. Single-Photon Scattering Grating in a Waveguide-Cavity System

    NASA Astrophysics Data System (ADS)

    Huang, Jin-Song; Li, Yan-Ling; Xu, Zhong-Hui; Huang, You-wen

    2016-04-01

    We investigate single-photon scattering grating in a one-dimensional waveguide coupled to a cavity embedded with a driven Λ-type three-level atom. The single-photon reflection amplitude and transmission amplitude in the waveguide are obtained via a real-space approach, respectively. By spatially modulating a classical control field to drive the three-level emitter, alternating regions of high reflection and absorption as well as high transmission and absorption of the single photon are generated in both directions of the waveguide, which acts as a kind of scattering grating. The proposed scheme may have the potential for the design of chip-integrated grating.

  10. Elliptical quantum dots as on-demand single photons sources with deterministic polarization states

    NASA Astrophysics Data System (ADS)

    Teng, Chu-Hsiang; Zhang, Lei; Hill, Tyler A.; Demory, Brandon; Deng, Hui; Ku, Pei-Cheng

    2015-11-01

    In quantum information, control of the single photon's polarization is essential. Here, we demonstrate single photon generation in a pre-programmed and deterministic polarization state, on a chip-scale platform, utilizing site-controlled elliptical quantum dots (QDs) synthesized by a top-down approach. The polarization from the QD emission is found to be linear with a high degree of linear polarization and parallel to the long axis of the ellipse. Single photon emission with orthogonal polarizations is achieved, and the dependence of the degree of linear polarization on the QD geometry is analyzed.

  11. A simple method for afterpulse probability measurement in high-speed single-photon detectors

    NASA Astrophysics Data System (ADS)

    Liu, Junliang; Li, Yongfu; Ding, Lei; Zhang, Chunfang; Fang, Jiaxiong

    2016-07-01

    A simple statistical method is proposed for afterpulse probability measurement in high-speed single-photon detectors. The method is based on in-laser-period counting without the support of time-correlated information or delay adjustment, and is readily implemented with commercially available logic devices. We present comparisons among the proposed method and commonly used methods which use the time-correlated single-photon counter or the gated counter, based on a 1.25-GHz gated infrared single-photon detector. Results show that this in-laser-period counting method has similar accuracy to the commonly used methods with extra simplicity, robustness, and faster measuring speed.

  12. Elliptical quantum dots as on-demand single photons sources with deterministic polarization states

    SciTech Connect

    Teng, Chu-Hsiang; Demory, Brandon; Ku, Pei-Cheng; Zhang, Lei; Hill, Tyler A.; Deng, Hui

    2015-11-09

    In quantum information, control of the single photon's polarization is essential. Here, we demonstrate single photon generation in a pre-programmed and deterministic polarization state, on a chip-scale platform, utilizing site-controlled elliptical quantum dots (QDs) synthesized by a top-down approach. The polarization from the QD emission is found to be linear with a high degree of linear polarization and parallel to the long axis of the ellipse. Single photon emission with orthogonal polarizations is achieved, and the dependence of the degree of linear polarization on the QD geometry is analyzed.

  13. Special properties of single-photon optical fiber sensor for security needs

    NASA Astrophysics Data System (ADS)

    Zyczkowski, M.; Szustakowski, M.; Karol, M.; Markowski, Piotr; Napierala, M. S.

    2014-10-01

    The rules of quantum physics are now fairly well understood and indisputable. On the basis of these principles are built safety systems to guarantee unconditional security of data transmission. This is possible due to the random behavior of the measured photon. Theorems of quantum mechanics are used currently in Quantum Key Distribution systems to determine the encryption key of cryptographic systems. Sending the single photons through the interferometer it is possible to determine the probability distribution of a photon detection at a given output depending on the interferometer imbalance. The use of single photon interference allows reduce the probability of detection of the transmission line protection. Additionally it provides high safety of transmitted information and minor disturbances. The quantum sensor can be a device which allows effectively protect transmission lines. In this paper we demonstrate measurement results of the using single-photon interferometers in security systems and potential capabilities use of such sensors.

  14. Towards linear optical detection with single photon sensitivity at telecom wavelengths

    NASA Astrophysics Data System (ADS)

    Jahanmirinejad, Saeedeh; Fiore, Andrea

    2012-06-01

    Standard linear optical detectors have a maximum sensitivity in the few hundreds of photons range, limited by amplifier noise. On the other hand, single photon detectors, which are the most sensitive detectors, are strongly nonlinear: One or more photons result in the same output signal. Photon number resolving (PNR) detectors, which have the ability to discriminate the number of photons in a weak optical pulse, are of great importance in the field of quantum information processing and quantum cryptography. Moreover, a PNR detector with large dynamic range can cover the gap between these two detection modes. Such detectors are greatly desirable not only in quantum information science and technology, but also in any application dealing with low light levels. In this work, we propose a novel approach to photon number resolving detectors based on spatial multiplexing of nanowire superconducting single-photon detectors. In the proposed approach, N superconducting nanowires, each connected in parallel to an integrated resistor, are connected in series. Photon absorption in a nanowire switches its bias current to the parallel resistor, forming a voltage pulse across it. The sum of these voltages, proportional to the number of absorbed photons, is measured at the output. The use of a cryogenic preamplifier with high input impedance for the read-out increases the linearity, the signal to noise ratio, and the speed. With this combination, we expect to be able to count up to few tens of photons with high fidelity, excellent timing resolution, and very high sensitivity in the telecommunication wavelength range.

  15. Generation of single photons with highly tunable wave shape from a cold atomic quantum memory

    NASA Astrophysics Data System (ADS)

    Heinze, Georg; Farrera, Pau; Albrecht, Boris; de Riedmatten, Hugues; Ho, Melvyn; Chavez, Matias; Teo, Colin; Sangouard, Nicolas

    2016-05-01

    We report on a single photon source with highly tunable photon shape based on a cold ensemble of Rubidium atoms. We follow the DLCZ scheme to implement an emissive quantum memory, which can be operated as a photon pair source with controllable delay. We find that the temporal wave shape of the emitted read photon can be precisely controlled by changing the shape of the driving read pulse. We generate photons with temporal durations varying over three orders of magnitude up to 10 μs without a significant change of the read-out efficiency. We prove the non-classicality of the emitted photons by measuring their antibunching, showing near single photon behavior at low excitation probabilities. We also show that the photons are emitted in a pure state by measuring unconditional autocorrelation functions. Finally, to demonstrate the usability of the source for realistic applications, we create ultra-long single photons with a rising exponential or doubly peaked time-bin wave shape which are important for several quantum information tasks. ICREA-Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain.

  16. Enhancement of Rydberg-mediated single-photon nonlinearities by electrically tuned Förster resonances

    PubMed Central

    Gorniaczyk, H.; Tresp, C.; Bienias, P.; Paris-Mandoki, A.; Li, W.; Mirgorodskiy, I.; Büchler, H. P.; Lesanovsky, I.; Hofferberth, S.

    2016-01-01

    Mapping the strong interaction between Rydberg atoms onto single photons via electromagnetically induced transparency enables manipulation of light at the single-photon level and few-photon devices such as all-optical switches and transistors operated by individual photons. Here we demonstrate experimentally that Stark-tuned Förster resonances can substantially increase this effective interaction between individual photons. This technique boosts the gain of a single-photon transistor to over 100, enhances the non-destructive detection of single Rydberg atoms to a fidelity beyond 0.8, and enables high-precision spectroscopy on Rydberg pair states. On top, we achieve a gain larger than 2 with gate photon read-out after the transistor operation. Theory models for Rydberg polariton propagation on Förster resonance and for the projection of the stored spin-wave yield excellent agreement to our data and successfully identify the main decoherence mechanism of the Rydberg transistor, paving the way towards photonic quantum gates. PMID:27515278

  17. Nonperturbative quantum solutions to resonant four-wave mixing of two single-photon wave packets

    SciTech Connect

    Johnsson, Mattias; Fleischhauer, Michael

    2003-08-01

    We analyze both analytically and numerically the resonant four-wave mixing of two co-propagating single-photon wave packets. We present analytic expressions for the two-photon wave function, and show that quantum solutions exist which display a shape-preserving oscillatory exchange of excitations between the modes. Potential applications including quantum-information processing are discussed.

  18. Enhancement of Rydberg-mediated single-photon nonlinearities by electrically tuned Förster resonances.

    PubMed

    Gorniaczyk, H; Tresp, C; Bienias, P; Paris-Mandoki, A; Li, W; Mirgorodskiy, I; Büchler, H P; Lesanovsky, I; Hofferberth, S

    2016-01-01

    Mapping the strong interaction between Rydberg atoms onto single photons via electromagnetically induced transparency enables manipulation of light at the single-photon level and few-photon devices such as all-optical switches and transistors operated by individual photons. Here we demonstrate experimentally that Stark-tuned Förster resonances can substantially increase this effective interaction between individual photons. This technique boosts the gain of a single-photon transistor to over 100, enhances the non-destructive detection of single Rydberg atoms to a fidelity beyond 0.8, and enables high-precision spectroscopy on Rydberg pair states. On top, we achieve a gain larger than 2 with gate photon read-out after the transistor operation. Theory models for Rydberg polariton propagation on Förster resonance and for the projection of the stored spin-wave yield excellent agreement to our data and successfully identify the main decoherence mechanism of the Rydberg transistor, paving the way towards photonic quantum gates. PMID:27515278

  19. Practical single-photon-assisted remote state preparation with non-maximally entanglement

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Huang, Ai-Jun; Sun, Wen-Yang; Shi, Jia-Dong; Ye, Liu

    2016-08-01

    Remote state preparation (RSP) and joint remote state preparation (JRSP) protocols for single-photon states are investigated via linear optical elements with partially entangled states. In our scheme, by choosing two-mode instances from a polarizing beam splitter, only the sender in the communication protocol needs to prepare an ancillary single-photon and operate the entanglement preparation process in order to retrieve an arbitrary single-photon state from a photon pair in partially entangled state. In the case of JRSP, i.e., a canonical model of RSP with multi-party, we consider that the information of the desired state is split into many subsets and in prior maintained by spatially separate parties. Specifically, with the assistance of a single-photon state and a three-photon entangled state, it turns out that an arbitrary single-photon state can be jointly and remotely prepared with certain probability, which is characterized by the coefficients of both the employed entangled state and the target state. Remarkably, our protocol is readily to extend to the case for RSP and JRSP of mixed states with the all optical means. Therefore, our protocol is promising for communicating among optics-based multi-node quantum networks.

  20. A single-photon detector in the far-infrared range

    PubMed

    Komiyama; Astafiev; Antonov; Kutsuwa; Hirai

    2000-01-27

    The far-infrared region (wavelengths in the range 10 microm-1 mm) is one of the richest areas of spectroscopic research, encompassing the rotational spectra of molecules and vibrational spectra of solids, liquids and gases. But studies in this spectral region are hampered by the absence of sensitive detectors--despite recent efforts to improve superconducting bolometers, attainable sensitivities are currently far below the level of single-photon detection. This is in marked contrast to the visible and near-infrared regions (wavelengths shorter than about 1.5 microm), in which single-photon counting is possible using photomultiplier tubes. Here we report the detection of single far-infrared photons in the wavelength range 175-210 microm (6.0-7.1 meV), using a single-electron transistor consisting of a semiconductor quantum dot in high magnetic field. We detect, with a time resolution of a millisecond, an incident flux of 0.1 photons per second on an effective detector area of 0.1 mm2--a sensitivity that exceeds previously reported values by a factor of more than 10(4). The sensitivity is a consequence of the unconventional detection mechanism, in which one absorbed photon leads to a current of 10(6)-10(12) electrons through the quantum dot. By contrast, mechanisms of conventional detectors or photon assisted tunnelling in single-electron transistors produce only a few electrons per incident photon. PMID:10667787

  1. Practical single-photon-assisted remote state preparation with non-maximally entanglement

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Huang, Ai-Jun; Sun, Wen-Yang; Shi, Jia-Dong; Ye, Liu

    2016-05-01

    Remote state preparation (RSP) and joint remote state preparation (JRSP) protocols for single-photon states are investigated via linear optical elements with partially entangled states. In our scheme, by choosing two-mode instances from a polarizing beam splitter, only the sender in the communication protocol needs to prepare an ancillary single-photon and operate the entanglement preparation process in order to retrieve an arbitrary single-photon state from a photon pair in partially entangled state. In the case of JRSP, i.e., a canonical model of RSP with multi-party, we consider that the information of the desired state is split into many subsets and in prior maintained by spatially separate parties. Specifically, with the assistance of a single-photon state and a three-photon entangled state, it turns out that an arbitrary single-photon state can be jointly and remotely prepared with certain probability, which is characterized by the coefficients of both the employed entangled state and the target state. Remarkably, our protocol is readily to extend to the case for RSP and JRSP of mixed states with the all optical means. Therefore, our protocol is promising for communicating among optics-based multi-node quantum networks.

  2. Complex photonic lattices embedded with tailored intrinsic defects by a dynamically reconfigurable single step interferometric approach

    SciTech Connect

    Xavier, Jolly Joseph, Joby

    2014-02-24

    We report sculptured diverse photonic lattices simultaneously embedded with intrinsic defects of tunable type, number, shape as well as position by a single-step dynamically reconfigurable fabrication approach based on a programmable phase spatial light modulator-assisted interference lithography. The presented results on controlled formation of intrinsic defects in periodic as well as transversely quasicrystallographic lattices, irrespective and independent of their designed lattice geometry, portray the flexibility and versatility of the approach. The defect-formation in photonic lattices is also experimentally analyzed. Further, we also demonstrate the feasibility of fabrication of such defects-embedded photonic lattices in a photoresist, aiming concrete integrated photonic applications.

  3. Simple, robust, and on-demand generation of single and correlated photons

    NASA Astrophysics Data System (ADS)

    Sathyamoorthy, Sankar Raman; Bengtsson, Andreas; Bens, Steven; Simoen, Michaël; Delsing, Per; Johansson, Göran

    2016-06-01

    We propose two different setups to generate single photons on demand using an atom in front of a mirror, along with either a beam splitter or a tunable coupling. We show that photon-generation efficiency of ˜99 % is straightforward to achieve. The proposed schemes are simple and easily tunable in frequency. The operation is relatively insensitive to dephasing and can be easily extended to generate correlated pairs of photons. They can also, in principle, be used to generate any photonic qubit of the form μ |0 >+ν |1 > in arbitrary wave packets, making them very attractive for quantum communication applications.

  4. Heralded Storage of a Photonic Quantum Bit in a Single Atom

    NASA Astrophysics Data System (ADS)

    Kalb, Norbert; Reiserer, Andreas; Ritter, Stephan; Rempe, Gerhard

    2015-06-01

    Combining techniques of cavity quantum electrodynamics, quantum measurement, and quantum feedback, we have realized the heralded transfer of a polarization qubit from a photon onto a single atom with 39% efficiency and 86% fidelity. The reverse process, namely, qubit transfer from the atom onto a given photon, is demonstrated with 88% fidelity and an estimated efficiency of up to 69%. In contrast to previous work based on two-photon interference, our scheme is robust against photon arrival-time jitter and achieves much higher efficiencies. Thus, it constitutes a key step toward the implementation of a long-distance quantum network.

  5. Heralded Storage of a Photonic Quantum Bit in a Single Atom.

    PubMed

    Kalb, Norbert; Reiserer, Andreas; Ritter, Stephan; Rempe, Gerhard

    2015-06-01

    Combining techniques of cavity quantum electrodynamics, quantum measurement, and quantum feedback, we have realized the heralded transfer of a polarization qubit from a photon onto a single atom with 39% efficiency and 86% fidelity. The reverse process, namely, qubit transfer from the atom onto a given photon, is demonstrated with 88% fidelity and an estimated efficiency of up to 69%. In contrast to previous work based on two-photon interference, our scheme is robust against photon arrival-time jitter and achieves much higher efficiencies. Thus, it constitutes a key step toward the implementation of a long-distance quantum network. PMID:26196608

  6. Information-holding quantum router of single photons using natural atom

    NASA Astrophysics Data System (ADS)

    Yan, Guo-An; Cai, Qing-Yu; Chen, Ai-Xi

    2016-04-01

    In a quantum network, a quantum router can play a key role that involves exchanging quantum information (quantum states) among different parties. In this paper, we propose a single-photon quantum router by using a four-level atom that is embedded in quantum multi-channels, which are composed of coupled-resonator waveguides. Single photons can be guided from one quantum channel to another by controlling an on-demand classical field. The fidelity of the routing atom recovers to a maximum after a time evolution cycle of the system; thus, the fidelity of the information-carrying single photon reaches unit at the same time. For the first time, we demonstrate that quantum information carried by single photons can be perfectly held after a quantum router.

  7. Single photon subradiance and superradiance revisited: a group theoretic analysis of subradiant states

    NASA Astrophysics Data System (ADS)

    Vetter, Philip A.; Wang, Luojia; Wang, Da-Wei; Scully, Marlan O.

    2016-02-01

    Single photon emission from a collection of resonantly excited two-level atoms is an expanding field. Recent work has shown single photon superradiance from an extended ensemble yields enhanced directional spontaneous emission. This paper presents an operator which commutes with the observables {{R}}2,{R}z and breaks their degeneracy for the single photon states. Its eigenvectors are a unimodular basis for the single photon states. A simple scheme is given for writing out these states directly without iterative construction and without requiring recourse to Gram-Schmidt orthogonalization. A relatively simple scheme is proposed for experimental realization. In the final part of the paper the mathematical method is extended to generate cooperative states with smaller cooperativity number R.

  8. Derivation of the density matrix of a single photon produced in parametric down-conversion

    SciTech Connect

    Kolenderski, Piotr; Wasilewski, Wojciech

    2009-07-15

    We discuss an effective numerical method of density matrix determination of fiber coupled single photon generated in process of spontaneous parametric down conversion in type I noncollinear configuration. The presented theory has been successfully applied in case of source utilized to demonstrate the experimental characterization of spectral state of single photon, what was reported in Wasilewski, Kolenderski, and Frankowski [Phys. Rev. Lett. 99, 123601 (2007)].

  9. Luminescence-induced noise in single photon sources based on BBO crystals

    NASA Astrophysics Data System (ADS)

    Machulka, Radek; Lemr, Karel; Haderka, Ondřej; Lamperti, Marco; Allevi, Alessia; Bondani, Maria

    2014-11-01

    Single-photon sources based on the process of spontaneous parametric down-conversion play a key role in various applied disciplines of quantum optics. We characterize the intrinsic luminescence of BBO crystals as a source of non-removable noise in quantum-optics experiments. By analysing its spectral and temporal properties together with its intensity, we evaluate the impact of luminescence on single-photon state preparation using spontaneous parametric down-conversion.

  10. Fast Excitation and Photon Emission of a Single-Atom-Cavity System

    SciTech Connect

    Bochmann, J.; Muecke, M.; Langfahl-Klabes, G.; Erbel, C.; Weber, B.; Specht, H. P.; Moehring, D. L.; Rempe, G.

    2008-11-28

    We report on the fast excitation of a single atom coupled to an optical cavity using laser pulses that are much shorter than all other relevant processes. The cavity frequency constitutes a control parameter that allows the creation of single photons in a superposition of two tunable frequencies. Each photon emitted from the cavity thus exhibits a pronounced amplitude modulation determined by the oscillatory energy exchange between the atom and the cavity. Our technique constitutes a versatile tool for future quantum networking experiments.

  11. A quantum phase switch between a single solid-state spin and a photon.

    PubMed

    Sun, Shuo; Kim, Hyochul; Solomon, Glenn S; Waks, Edo

    2016-06-01

    Interactions between single spins and photons are essential for quantum networks and distributed quantum computation. Achieving spin-photon interactions in a solid-state device could enable compact chip-integrated quantum circuits operating at gigahertz bandwidths. Many theoretical works have suggested using spins embedded in nanophotonic structures to attain this high-speed interface. These proposals implement a quantum switch where the spin flips the state of the photon and a photon flips the spin state. However, such a switch has not yet been realized using a solid-state spin system. Here, we report an experimental realization of a spin-photon quantum switch using a single solid-state spin embedded in a nanophotonic cavity. We show that the spin state strongly modulates the polarization of a reflected photon, and a single reflected photon coherently rotates the spin state. These strong spin-photon interactions open up a promising direction for solid-state implementations of high-speed quantum networks and on-chip quantum information processors using nanophotonic devices. PMID:26854569

  12. A quantum phase switch between a single solid-state spin and a photon

    NASA Astrophysics Data System (ADS)

    Sun, Shuo; Kim, Hyochul; Solomon, Glenn S.; Waks, Edo

    2016-06-01

    Interactions between single spins and photons are essential for quantum networks and distributed quantum computation. Achieving spin–photon interactions in a solid-state device could enable compact chip-integrated quantum circuits operating at gigahertz bandwidths. Many theoretical works have suggested using spins embedded in nanophotonic structures to attain this high-speed interface. These proposals implement a quantum switch where the spin flips the state of the photon and a photon flips the spin state. However, such a switch has not yet been realized using a solid-state spin system. Here, we report an experimental realization of a spin–photon quantum switch using a single solid-state spin embedded in a nanophotonic cavity. We show that the spin state strongly modulates the polarization of a reflected photon, and a single reflected photon coherently rotates the spin state. These strong spin–photon interactions open up a promising direction for solid-state implementations of high-speed quantum networks and on-chip quantum information processors using nanophotonic devices.

  13. Single-Photon Depth Imaging Using a Union-of-Subspaces Model

    NASA Astrophysics Data System (ADS)

    Shin, Dongeek; Shapiro, Jeffrey H.; Goyal, Vivek K.

    2015-12-01

    Light detection and ranging systems reconstruct scene depth from time-of-flight measurements. For low light-level depth imaging applications, such as remote sensing and robot vision, these systems use single-photon detectors that resolve individual photon arrivals. Even so, they must detect a large number of photons to mitigate Poisson shot noise and reject anomalous photon detections from background light. We introduce a novel framework for accurate depth imaging using a small number of detected photons in the presence of an unknown amount of background light that may vary spatially. It employs a Poisson observation model for the photon detections plus a union-of-subspaces constraint on the discrete-time flux from the scene at any single pixel. Together, they enable a greedy signal-pursuit algorithm to rapidly and simultaneously converge on accurate estimates of scene depth and background flux, without any assumptions on spatial correlations of the depth or background flux. Using experimental single-photon data, we demonstrate that our proposed framework recovers depth features with 1.7 cm absolute error, using 15 photons per image pixel and an illumination pulse with 6.7-cm scaled root-mean-square length. We also show that our framework outperforms the conventional pixelwise log-matched filtering, which is a computationally-efficient approximation to the maximum-likelihood solution, by a factor of 6.1 in absolute depth error.

  14. High-fidelity transfer and storage of photon states in a single nuclear spin

    NASA Astrophysics Data System (ADS)

    Yang, Sen; Wang, Ya; Rao, D. D. Bhaktavatsala; Hien Tran, Thai; Momenzadeh, Ali S.; Markham, M.; Twitchen, D. J.; Wang, Ping; Yang, Wen; Stöhr, Rainer; Neumann, Philipp; Kosaka, Hideo; Wrachtrup, Jörg

    2016-08-01

    Long-distance quantum communication requires photons and quantum nodes that comprise qubits for interaction with light and good memory capabilities, as well as processing qubits for the storage and manipulation of photons. Owing to the unavoidable photon losses, robust quantum communication over lossy transmission channels requires quantum repeater networks. A necessary and highly demanding prerequisite for these networks is the existence of quantum memories with long coherence times to reliably store the incident photon states. Here we demonstrate the high-fidelity (∼98%) coherent transfer of a photon polarization state to a single solid-state nuclear spin that has a coherence time of over 10 s. The storage process is achieved by coherently transferring the polarization state of a photon to an entangled electron–nuclear spin state of a nitrogen–vacancy centre in diamond. The nuclear spin-based optical quantum memory demonstrated here paves the way towards an absorption-based quantum repeater network.

  15. Tailored-waveguide based photonic chip for manipulating an array of single neutral atoms.

    PubMed

    Ke, Min; Zhou, Feng; Li, Xiao; Wang, Jin; Zhan, Mingsheng

    2016-05-01

    We propose a tailored-waveguide based photonic chip with the functions of trapping, coherently manipulating, detecting and individually addressing an array of single neutral atoms. Such photonic chip consists of an array of independent functional units spaced by a few micrometers, each of which is comprised of one silica-on-silicon optical waveguide and one phase Fresnel microlens etched in the middle of the output interface of the optical waveguide. We fabricated a number of photonic chips with 7 functional units and measured optical characteristics of these chips. We further propose feasible schemes to realize the functions of such photonic chip. The photonic chip is stable, scalable and can be combined with other integrated devices, such as atom chips, and can be used in the future hybrid quantum system and photonic quantum devices. PMID:27137532

  16. Quantum storage of heralded single photons in a praseodymium-doped crystal.

    PubMed

    Rieländer, Daniel; Kutluer, Kutlu; Ledingham, Patrick M; Gündoğan, Mustafa; Fekete, Julia; Mazzera, Margherita; de Riedmatten, Hugues

    2014-01-31

    We report on experiments demonstrating the reversible mapping of heralded single photons to long-lived collective optical atomic excitations stored in a Pr3+:Y2SiO5 crystal. A cavity-enhanced spontaneous down-conversion source is employed to produce widely nondegenerate narrow-band (≈2  MHz) photon pairs. The idler photons, whose frequency is compatible with telecommunication optical fibers, are used to herald the creation of the signal photons, compatible with the Pr3+ transition. The signal photons are stored and retrieved using the atomic frequency comb protocol. We demonstrate storage times up to 4.5  μs while preserving nonclassical correlations between the heralding and the retrieved photon. This is more than 20 times longer than in previous realizations in solid state devices, and implemented in a system ideally suited for the extension to spin-wave storage. PMID:24580428

  17. An ultra-fast superconducting Nb nanowire single-photon detector for soft x-rays

    SciTech Connect

    Inderbitzin, K.; Engel, A.; Schilling, A.; Il'in, K.; Siegel, M.

    2012-10-15

    Although superconducting nanowire single-photon detectors (SNSPDs) are well studied regarding the detection of infrared/optical photons and keV-molecules, no studies on continuous x-ray photon counting by thick-film detectors have been reported so far. We fabricated a 100 nm thick niobium x-ray SNSPD (an X-SNSPD) and studied its detection capability of photons with keV-energies in continuous mode. The detector is capable to detect photons even at reduced bias currents of 0.4%, which is in sharp contrast to optical thin-film SNSPDs. No dark counts were recorded in extended measurement periods. Strikingly, the signal amplitude distribution depends significantly on the photon energy spectrum.

  18. On-chip electrically controlled routing of photons from a single quantum dot

    SciTech Connect

    Bentham, C.; Coles, R. J.; Royall, B.; O'Hara, J.; Prtljaga, N.; Fox, A. M.; Skolnick, M. S.; Wilson, L. R.; Itskevich, I. E.; Clarke, E.

    2015-06-01

    Electrical control of on-chip routing of photons emitted by a single InAs/GaAs self-assembled quantum dot (SAQD) is demonstrated in a photonic crystal cavity-waveguide system. The SAQD is located inside an H1 cavity, which is coupled to two photonic crystal waveguides. The SAQD emission wavelength is electrically tunable by the quantum-confined Stark effect. When the SAQD emission is brought into resonance with one of two H1 cavity modes, it is preferentially routed to the waveguide to which that mode is selectively coupled. This proof of concept provides the basis for scalable, low-power, high-speed operation of single-photon routers for use in integrated quantum photonic circuits.

  19. Coherent perfect absorption in deeply subwavelength films in the single-photon regime

    PubMed Central

    Roger, Thomas; Vezzoli, Stefano; Bolduc, Eliot; Valente, Joao; Heitz, Julius J. F.; Jeffers, John; Soci, Cesare; Leach, Jonathan; Couteau, Christophe; Zheludev, Nikolay I.; Faccio, Daniele

    2015-01-01

    The technologies of heating, photovoltaics, water photocatalysis and artificial photosynthesis depend on the absorption of light and novel approaches such as coherent absorption from a standing wave promise total dissipation of energy. Extending the control of absorption down to very low light levels and eventually to the single-photon regime is of great interest and yet remains largely unexplored. Here we demonstrate the coherent absorption of single photons in a deeply subwavelength 50% absorber. We show that while the absorption of photons from a travelling wave is probabilistic, standing wave absorption can be observed deterministically, with nearly unitary probability of coupling a photon into a mode of the material, for example, a localized plasmon when this is a metamaterial excited at the plasmon resonance. These results bring a better understanding of the coherent absorption process, which is of central importance for light harvesting, detection, sensing and photonic data processing applications. PMID:25991584

  20. Coherent perfect absorption in deeply subwavelength films in the single-photon regime

    NASA Astrophysics Data System (ADS)

    Roger, Thomas; Vezzoli, Stefano; Bolduc, Eliot; Valente, Joao; Heitz, Julius J. F.; Jeffers, John; Soci, Cesare; Leach, Jonathan; Couteau, Christophe; Zheludev, Nikolay I.; Faccio, Daniele

    2015-05-01

    The technologies of heating, photovoltaics, water photocatalysis and artificial photosynthesis depend on the absorption of light and novel approaches such as coherent absorption from a standing wave promise total dissipation of energy. Extending the control of absorption down to very low light levels and eventually to the single-photon regime is of great interest and yet remains largely unexplored. Here we demonstrate the coherent absorption of single photons in a deeply subwavelength 50% absorber. We show that while the absorption of photons from a travelling wave is probabilistic, standing wave absorption can be observed deterministically, with nearly unitary probability of coupling a photon into a mode of the material, for example, a localized plasmon when this is a metamaterial excited at the plasmon resonance. These results bring a better understanding of the coherent absorption process, which is of central importance for light harvesting, detection, sensing and photonic data processing applications.

  1. Bright single photon source based on self-aligned quantum dot-cavity systems.

    PubMed

    Maier, Sebastian; Gold, Peter; Forchel, Alfred; Gregersen, Niels; Mørk, Jesper; Höfling, Sven; Schneider, Christian; Kamp, Martin

    2014-04-01

    We report on a quasi-planar quantum-dot-based single-photon source that shows an unprecedented high extraction efficiency of 42% without complex photonic resonator geometries or post-growth nanofabrication. This very high efficiency originates from the coupling of the photons emitted by a quantum dot to a Gaussian shaped nanohill defect that naturally arises during epitaxial growth in a self-aligned manner. We investigate the morphology of these defects and characterize the photonic operation mechanism. Our results show that these naturally arising coupled quantum dot-defects provide a new avenue for efficient (up to 42% demonstrated) and pure (g(2)(0) value of 0.023) single-photon emission. PMID:24718190

  2. Broad working bandwidth and "endlessly" single-mode guidance within hybrid silicon photonics.

    PubMed

    Bougot-Robin, K; Hugonin, J-P; Besbes, M; Benisty, H

    2015-08-01

    The successes of nonlinear photonics and hybrid silicon photonics with a growing variety of functional materials entail ever-enlarging bandwidths. It is best exemplified by parametric comb frequency generation. Such operation challenges the dielectric channel waveguide as the basis for guidance, because of the adverse advent of higher order modes at short wavelengths. Surprisingly, the popular mechanism of endlessly single-mode guidance [Opt. Lett.22, 961 (1997).] operating in photonic crystal fibers has not been transposed within silicon photonics yet. We outline here the strategy and potential of this approach within planar and hybrid silicon photonics, whereby in-plane and vertical confinement are shown to be amenable to near-single-mode behavior in the typical silicon band, i.e., λ=1.1  μm to ∼5  μm. PMID:26258345

  3. A quantum dot single-photon source with on-the-fly all-optical polarization control and timed emission

    NASA Astrophysics Data System (ADS)

    Heinze, Dirk; Breddermann, Dominik; Zrenner, Artur; Schumacher, Stefan

    2015-10-01

    Sources of single photons are key elements for applications in quantum information science. Among the different sources available, semiconductor quantum dots excel with their integrability in semiconductor on-chip solutions and the potential that photon emission can be triggered on demand. Usually, the photon is emitted from a single-exciton ground state. Polarization of the photon and time of emission are either probabilistic or pre-determined by electronic properties of the system. Here, we study the direct two-photon emission from the biexciton. The two-photon emission is enabled by a laser pulse driving the system into a virtual state inside the band gap. From this intermediate state, the single photon of interest is then spontaneously emitted. We show that emission through this higher-order transition provides a versatile approach to generate a single photon. Through the driving laser pulse, polarization state, frequency and emission time of the photon can be controlled on-the-fly.

  4. Nano-LED array fabrication suitable for future single photon lithography

    NASA Astrophysics Data System (ADS)

    Mikulics, M.; Hardtdegen, H.

    2015-05-01

    We report on an alternative illumination concept for a future lithography based on single-photon emitters and important technological steps towards its implementation. Nano light-emitting diodes (LEDs) are chosen as the photon emitters. First, the development of their fabrication and their integration technology is presented, then their optical characteristics assessed. Last, size-controlled nano-LEDs, well positioned in an array, are electrically driven and utilized for illumination. Nanostructures are lithographically formed, demonstrating the feasibility of the approach. The potential of single-photon lithography to reach the ultimate scale limits in mass production is discussed.

  5. Quantum teleportation through an entangled state composed of displaced vacuum and single-photon states

    SciTech Connect

    Podoshvedov, S. A.

    2008-03-15

    We study a teleportation protocol of an unknown macroscopic qubit by means of a quantum channel composed of the displaced vacuum and single-photon states. The scheme is based on linear optical devices such as a beam splitter and photon number resolving detectors. A method based on conditional measurement is used to generate both the macroscopic qubit and entangled state composed from displaced vacuum and single-photon states. We show that such a qubit has both macroscopic and microscopic properties. In particular, we investigate a quantum teleportation protocol from a macroscopic object to a microscopic state.

  6. Single telecom photon heralding by wavelength multiplexing in an optical fiber

    NASA Astrophysics Data System (ADS)

    Lenhard, Andreas; Brito, José; Kucera, Stephan; Bock, Matthias; Eschner, Jürgen; Becher, Christoph

    2016-01-01

    We demonstrate the multiplexing of a weak coherent and a quantum state of light in a single telecommunication fiber. For this purpose, we make use of spontaneous parametric down conversion and quantum frequency conversion to generate photon pairs at 854 nm and the telecom O-band. The herald photon at 854 nm triggers a telecom C-band laser pulse. The telecom single photon (O-band) and the laser pulse (C-band) are combined and coupled to a standard telecom fiber. Low-background time correlation between the weak coherent and quantum signal behind the fiber shows successful multiplexing.

  7. Surface acoustic wave regulated single photon emission from a coupled quantum dot-nanocavity system

    NASA Astrophysics Data System (ADS)

    Weiß, M.; Kapfinger, S.; Reichert, T.; Finley, J. J.; Wixforth, A.; Kaniber, M.; Krenner, H. J.

    2016-07-01

    A coupled quantum dot-nanocavity system in the weak coupling regime of cavity-quantumelectrodynamics is dynamically tuned in and out of resonance by the coherent elastic field of a fSAW ≃ 800 MHz surface acoustic wave. When the system is brought to resonance by the sound wave, light-matter interaction is strongly increased by the Purcell effect. This leads to a precisely timed single photon emission as confirmed by the second order photon correlation function, g(2). All relevant frequencies of our experiment are faithfully identified in the Fourier transform of g(2), demonstrating high fidelity regulation of the stream of single photons emitted by the system.

  8. Electronic-state-controlled reset operation in quantum dot resonant-tunneling single-photon detectors

    SciTech Connect

    Weng, Q. C.; Zhu, Z. Q.; An, Z. H.; Song, J. D.; Choi, W. J.

    2014-02-03

    The authors present a systematic study of an introduced reset operation on quantum dot (QD) single photon detectors operating at 77 K. The detectors are based on an AlAs/GaAs/AlAs double-barrier resonant tunneling diode with an adjacent layer of self-assembled InAs QDs. Sensitive single-photon detection in high (dI)/(dV) region with suppressed current fluctuations is achieved. The dynamic detection range is extended up to at least 10{sup 4} photons/s for sensitive imaging applications by keeping the device far from saturation by employing an appropriate reset frequency.

  9. Single photon transport in two waveguides chirally coupled by a quantum emitter.

    PubMed

    Cheng, Mu-Tian; Ma, Xiao-San; Zhang, Jia-Yan; Wang, Bing

    2016-08-22

    We investigate single photon transport in two waveguides coupled to a two-level quantum emitter (QE). With the deduced analytical scattering amplitudes, we show that under condition of the chiral coupling between the QE and the photon in the two waveguides, the QE can play the role of ideal quantum router to redirect a single photon incident from one waveguide into the other waveguide with a probability of 100% in the ideal condition. The influences of cross coupling between two waveguides and dissipations on the routing are also shown. PMID:27557274

  10. An on-chip coupled resonator optical waveguide single-photon buffer

    PubMed Central

    Takesue, Hiroki; Matsuda, Nobuyuki; Kuramochi, Eiichi; Munro, William J.; Notomi, Masaya

    2013-01-01

    Integrated quantum optical circuits are now seen as one of the most promising approaches with which to realize single-photon quantum information processing. Many of the core elements for such circuits have been realized, including sources, gates and detectors. However, a significant missing function necessary for photonic quantum information processing on-chip is a buffer, where single photons are stored for a short period of time to facilitate circuit synchronization. Here we report an on-chip single-photon buffer based on coupled resonator optical waveguides (CROW) consisting of 400 high-Q photonic crystal line-defect nanocavities. By using the CROW, a pulsed single photon is successfully buffered for 150 ps with 50-ps tunability while maintaining its non-classical properties. Furthermore, we show that our buffer preserves entanglement by storing and retrieving one photon from a time-bin entangled state. This is a significant step towards an all-optical integrated quantum information processor. PMID:24217422

  11. Ultrabright single-photon source on diamond with electrical pumping at room and high temperatures

    NASA Astrophysics Data System (ADS)

    Fedyanin, D. Yu; Agio, M.

    2016-07-01

    The recently demonstrated electroluminescence of color centers in diamond makes them one of the best candidates for room temperature single-photon sources. However, the reported emission rates are far off what can be achieved by state-of-the-art electrically driven epitaxial quantum dots. Since the electroluminescence mechanism has not yet been elucidated, it is not clear to what extent the emission rate can be increased. Here we develop a theoretical framework to study single-photon emission from color centers in diamond under electrical pumping. The proposed model comprises electron and hole trapping and releasing, transitions between the ground and excited states of the color center as well as structural transformations of the center due to carrier trapping. It provides the possibility to predict both the photon emission rate and the wavelength of emitted photons. Self-consistent numerical simulations of the single-photon emitting diode based on the proposed model show that the photon emission rate can be as high as 100 kcounts s‑1 at standard conditions. In contrast to most optoelectronic devices, the emission rate steadily increases with the device temperature achieving of more than 100 Mcount s‑1 at 500 K, which is highly advantageous for practical applications. These results demonstrate the potential of color centers in diamond as electrically driven non-classical light emitters and provide a foundation for the design and development of single-photon sources for optical quantum computation and quantum communication networks operating at room and higher temperatures.

  12. Near-optimal single-photon sources in the solid state

    NASA Astrophysics Data System (ADS)

    Somaschi, N.; Giesz, V.; de Santis, L.; Loredo, J. C.; Almeida, M. P.; Hornecker, G.; Portalupi, S. L.; Grange, T.; Antón, C.; Demory, J.; Gómez, C.; Sagnes, I.; Lanzillotti-Kimura, N. D.; Lemaítre, A.; Auffeves, A.; White, A. G.; Lanco, L.; Senellart, P.

    2016-05-01

    The scaling of optical quantum technologies requires efficient, on-demand sources of highly indistinguishable single photons. Semiconductor quantum dots inserted into photonic structures are ultrabright single-photon sources, yet the indistinguishability is limited by charge noise. Parametric downconversion sources provide highly indistinguishable photons but are operated at very low brightness to maintain high single-photon purity. To date, no technology has provided a bright source generating near-unity indistinguishability and pure single photons. Here, we report such devices made of quantum dots in electrically controlled cavities. Application of an electrical bias on the deterministically fabricated structures is shown to strongly reduce charge noise. Under resonant excitation, an indistinguishability of 0.9956 ± 0.0045 is demonstrated with g(2)(0) = 0.0028 ± 0.0012. The photon extraction of 65% and measured brightness of 0.154 ± 0.015 make this source 20 times brighter than any source of equal quality. This new generation of sources opens the way to new levels of complexity and scalability in optical quantum technologies.

  13. Generating single-photon catalyzed coherent states with quantum-optical catalysis

    NASA Astrophysics Data System (ADS)

    Xu, Xue-xiang; Yuan, Hong-chun

    2016-07-01

    We theoretically generate single-photon catalyzed coherent states (SPCCSs) by means of quantum-optical catalysis based on the beam splitter (BS) or the parametric amplifier (PA). These states are obtained in one of the BS (or PA) output channels if a coherent state and a single-photon Fock state are present in two input ports and a single photon is registered in the other output port. The success probabilities of the detection (also the normalization factors) are discussed, which is different for BS and PA catalysis. In addition, we prove that the generated states catalyzed by BS and PA devices are actually the same quantum states after analyzing photon number distribution of the SPCCSs. The quantum properties of the SPCCSs, such as sub-Poissonian distribution, anti-bunching effect, quadrature squeezing effect, and the negativity of the Wigner function are investigated in detail. The results show that the SPCCSs are non-Gaussian states with an abundance of nonclassicality.

  14. Heralded single-photon sources for quantum-key-distribution applications

    NASA Astrophysics Data System (ADS)

    Schiavon, Matteo; Vallone, Giuseppe; Ticozzi, Francesco; Villoresi, Paolo

    2016-01-01

    Single-photon sources (SPSs) are a fundamental building block for optical implementations of quantum information protocols. Among SPSs, multiple crystal heralded single-photon sources seem to give the best compromise between high pair production rate and low multiple photon events. In this work, we study their performance in a practical quantum-key-distribution experiment, by evaluating the achievable key rates. The analysis focuses on the two different schemes, symmetric and asymmetric, proposed for the practical implementation of heralded single-photon sources, with attention on the performance of their composing elements. The analysis is based on the protocol proposed by Bennett and Brassard in 1984 and on its improvement exploiting decoy state technique. Finally, a simple way of exploiting the postselection mechanism for a passive, one decoy state scheme is evaluated.

  15. cGMP in mouse rods: the spatiotemporal dynamics underlying single photon responses

    PubMed Central

    Pugh Jr., Edward N.; Burns, Marie E.

    2015-01-01

    Vertebrate vision begins when retinal photoreceptors transduce photons into electrical signals that are then relayed to other neurons in the eye, and ultimately to the brain. In rod photoreceptors, transduction of single photons is achieved by a well-understood G-protein cascade that modulates cGMP levels, and in turn, cGMP-sensitive inward current. The spatial extent and depth of the decline in cGMP during the single photon response (SPR) have been major issues in phototransduction research since the discovery that single photons elicit substantial and reproducible changes in membrane current. The spatial profile of cGMP decline during the SPR affects signal gain, and thus may contribute to reduction of trial-to-trial fluctuations in the SPR. Here we summarize the general principles of rod phototransduction, emphasizing recent advances in resolving the spatiotemporal dynamics of cGMP during the SPR. PMID:25788876

  16. Multiplexed single-photon-state preparation using a fiber-loop architecture

    NASA Astrophysics Data System (ADS)

    Rohde, Peter P.; Helt, L. G.; Steel, M. J.; Gilchrist, Alexei

    2015-11-01

    Heralded spontaneous parametric down-conversion (SPDC) has become the mainstay for single-photon-state preparation in present-day photonics experiments. Because they are heralded, in principle one knows when a single photon has been prepared. However, the heralding efficiencies in experimentally realistic SPDC sources are typically very low. To overcome this, multiplexing techniques have been proposed which employ a bank of SPDC sources in parallel and route successfully heralded photons to the output, thereby effectively boosting the heralding efficiency. However, running a large bank of independent SPDC sources is costly and requires complex switching. We analyze a multiplexing technique based on time-bin encoding that allows the heralding efficiency of just a single SPDC source to be increased. The scheme is simple and experimentally viable using present-day technology. We analyze the operation of the scheme in terms of experimentally realistic considerations, such as losses, detector inefficiency, and pump power.

  17. Quantum teleportation between a single-rail single-photon qubit and a coherent-state qubit using hybrid entanglement under decoherence effects

    NASA Astrophysics Data System (ADS)

    Jeong, Hyunseok; Bae, Seunglee; Choi, Seongjeon

    2016-02-01

    We study quantum teleportation between two different types of optical qubits using hybrid entanglement as a quantum channel under decoherence effects. One type of qubit employs the vacuum and single-photon states for the basis, called a single-rail single-photon qubit, and the other utilizes coherent states of opposite phases. We find that teleportation from a single-rail single-photon qubit to a coherent-state qubit is better than the opposite direction in terms of fidelity and success probability. We compare our results with those using a different type of hybrid entanglement between a polarized single-photon qubit and a coherent state.

  18. Single-photon single ionization of W+ ions: experiment and theory

    NASA Astrophysics Data System (ADS)

    Müller, A.; Schippers, S.; Hellhund, J.; Holste, K.; Kilcoyne, A. L. D.; Phaneuf, R. A.; Ballance, C. P.; McLaughlin, B. M.

    2015-12-01

    Experimental and theoretical results are reported for photoionization of Ta-like (W+) tungsten ions. Absolute cross sections were measured in the energy range 16-245 eV employing the photon-ion merged-beam setup at the advanced light source in Berkeley. Detailed photon-energy scans at 100 meV bandwidth were performed in the 16-108 eV range. In addition, the cross section was scanned at 50 meV resolution in regions where fine resonance structures could be observed. Theoretical results were obtained from a Dirac-Coulomb R-matrix approach. Photoionization cross section calculations were performed for singly ionized atomic tungsten ions in their 5{{{s}}}25{{{p}}}65{{{d}}}4{(}5{{D}})6{{s}}{ }6{{{D}}}J, J = 1/2, ground level and the associated excited metastable levels with J = 3/2, 5/2, 7/2 and 9/2. Since the ion beams used in the experiments must be expected to contain long-lived excited states also from excited configurations, additional cross-section calculations were performed for the second-lowest term, 5{{{d}}}5{ }6{{{S}}}J, J = 5/2, and for the 4F term, 5{{{d}}}36{{{s}}}2{ }4{{{F}}}J, with J = 3/2, 5/2, 7/2 and 9/2. Given the complexity of the electronic structure of W+ the calculations reproduce the main features of the experimental cross section quite well.

  19. Electrically driven photon antibunching from a single molecule at room temperature.

    PubMed

    Nothaft, Maximilian; Höhla, Steffen; Jelezko, Fedor; Frühauf, Norbert; Pflaum, Jens; Wrachtrup, Jörg

    2012-01-01

    Single-photon emitters have been considered for applications in quantum information processing, quantum cryptography and metrology. For the sake of integration and to provide an electron photon interface, it is of great interest to stimulate single-photon emission by electrical excitation as demonstrated for quantum dots. Because of low exciton binding energies, it has so far not been possible to detect sub-Poissonian photon statistics of electrically driven quantum dots at room temperature. However, organic molecules possess exciton binding energies on the order of 1eV, thereby facilitating the development of an electrically driven single-photon source at room temperature in a solid-state matrix. Here we demonstrate electroluminescence of single, electrically driven molecules at room temperature. By careful choice of the molecular emitter, as well as fabrication of a specially designed organic light-emitting diode structure, we were able to achieve stable single-molecule emission and detect sub-Poissonian photon statistics. PMID:22252552

  20. Single-Photon Avalanche Diodes (SPAD) in CMOS 0.35 μm technology

    NASA Astrophysics Data System (ADS)

    Pellion, D.; Jradi, K.; Brochard, N.; Prêle, D.; Ginhac, D.

    2015-07-01

    Some decades ago single photon detection used to be the terrain of photomultiplier tube (PMT), thanks to its characteristics of sensitivity and speed. However, PMT has several disadvantages such as low quantum efficiency, overall dimensions, and cost, making them unsuitable for compact design of integrated systems. So, the past decade has seen a dramatic increase in interest in new integrated single-photon detectors called Single-Photon Avalanche Diodes (SPAD) or Geiger-mode APD. SPAD are working in avalanche mode above the breakdown level. When an incident photon is captured, a very fast avalanche is triggered, generating an easily detectable current pulse. This paper discusses SPAD detectors fabricated in a standard CMOS technology featuring both single-photon sensitivity, and excellent timing resolution, while guaranteeing a high integration. In this work, we investigate the design of SPAD detectors using the AMS 0.35 μm CMOS Opto technology. Indeed, such standard CMOS technology allows producing large surface (few mm2) of single photon sensitive detectors. Moreover, SPAD in CMOS technologies could be associated to electronic readout such as active quenching, digital to analog converter, memories and any specific processing required to build efficient calorimeters1

  1. Demonstration of digital readout circuit for superconducting nanowire single photon detector.

    PubMed

    Ortlepp, T; Hofherr, M; Fritzsch, L; Engert, S; Ilin, K; Rall, D; Toepfer, H; Meyer, H-G; Siegel, M

    2011-09-12

    We demonstrate the transfer of single photon triggered electrical pulses from a superconducting nanowire single photon detector (SNSPD) to a single flux quantum (SFQ) pulse. We describe design and test of a digital SFQ based SNSPD readout circuit and demonstrate its correct operation. Both circuits (SNSPD and SFQ) operate under the same cryogenic conditions and are directly connected by wire bonds. A future integration of the present multi-chip configuration seems feasible because both fabrication process and materials are very similar. In contrast to commonly used semiconductor amplifiers, SFQ circuits combine very low power dissipation (a few microwatts) with very high operation speed, thus enabling count-rates of several gigahertz. The SFQ interface circuit simplifies the SNSPD readout and enables large numbers of detectors for future compact multi-pixel systems with single photon counting resolution. The demonstrated circuit has great potential for scaling the present interface solution to 1,000 detectors by using a single SFQ chip. PMID:21935228

  2. New cardiac cameras: single-photon emission CT and PET.

    PubMed

    Slomka, Piotr J; Berman, Daniel S; Germano, Guido

    2014-07-01

    Nuclear cardiology instrumentation has evolved significantly in the recent years. Concerns about radiation dose and long acquisition times have propelled developments of dedicated high-efficiency cardiac SPECT scanners. Novel collimator designs, such as multipinhole or locally focusing collimators arranged in geometries that are optimized for cardiac imaging, have been implemented to enhance photon-detection sensitivity. Some of these new SPECT scanners use solid-state photon detectors instead of photomultipliers to improve image quality and to reduce the scanner footprint. These new SPECT devices allow dramatic up to 7-fold reduction in acquisition times or similar reduction in radiation dose. In addition, new hardware for photon attenuation correction allowing ultralow radiation doses has been offered by some vendors. To mitigate photon attenuation artifacts for the new SPECT scanners not equipped with attenuation correction hardware, 2-position (upright-supine or prone-supine) imaging has been proposed. PET hardware developments have been primarily driven by the requirements of oncologic imaging, but cardiac imaging can benefit from improved PET image quality and improved sensitivity of 3D systems. The time-of-flight reconstruction combined with resolution recovery techniques is now implemented by all major PET vendors. These new methods improve image contrast and image resolution and reduce image noise. High-sensitivity 3D PET without interplane septa allows reduced radiation dose for cardiac perfusion imaging. Simultaneous PET/MR hybrid system has been developed. Solid-state PET detectors with avalanche photodiodes or digital silicon photomultipliers have been introduced, and they offer improved imaging characteristics and reduced sensitivity to electromagnetic MR fields. Higher maximum count rate of the new PET detectors allows routine first-pass Rb-82 imaging, with 3D PET acquisition enabling clinical utilization of dynamic imaging with myocardial flow

  3. Experimental Realization of Efficient, Room Temperature Single-Photon Sources with Definite Circular and Linear Polarizations

    NASA Astrophysics Data System (ADS)

    Boutsidis, Christos

    In this thesis I present experimental demonstrations of room-temperature, single-photon sources with definite linear and circular polarizations. Definite photon polarization increases the efficiency of quantum communication systems. In contrast with cryogenic-temperature single-photon sources based on epitaxial quantum dots requiring expensive MBE and nanofabrication, my method utilizes a mature liquid crystal technology, which I made consistent with single-emitter fluorescence microscopy. The structures I have prepared are planar-aligned cholesteric liquid crystals forming 1-D photonic bandgaps for circularly-polarized light, which were used to achieve definite circularly-polarized fluorescence of single emitters doped in this environment. I also used planar-aligned nematic liquid crystals to align single molecules with linear dipole moments and achieved definite linearly-polarized fluorescence. I used single nanocrystal quantum dots, single nanodiamond color-centers, rare-earth-doped nanocrystals, and single terrylene and DiIC18(3) dye molecules as emitters. For nanocrystal quantum dots I observed circular polarization dissymmetry factors as large as ge = --1.6. In addition, I observed circularly-polarized resonances in the fluorescence of emitters within a cholesteric microcavity, with cavity quality factors of up to Q ˜ 250. I also showed that the fluorescence of DiIC18(3) dye molecules in planar-aligned nematic cells exhibits definite linear polarization, with a degree of polarization of rho = --0.58 +/- 0.03. Distributed Bragg reflectors form another type of microcavity that can be used to realize a single-photon source. I characterized the fluorescence from nanocrystal quantum dots doped in the defect layers of such microcavites, both organic and inorganic. Finally, to demonstrate the single-photon properties of single-emitter-doped cholesteric and nematic liquid crystal structures and distributed Bragg reflector microcavities, I present observations of

  4. Generation and efficient measurement of single photons from fixed-frequency superconducting qubits

    NASA Astrophysics Data System (ADS)

    Kindel, William F.; Schroer, M. D.; Lehnert, K. W.

    2016-03-01

    We demonstrate and evaluate an on-demand source of single itinerant microwave photons. Photons are generated using a highly coherent, fixed-frequency qubit-cavity system, and a protocol where the microwave control field is far detuned from the photon emission frequency. By using a Josephson parametric amplifier (JPA), we perform efficient single-quadrature detection of the state emerging from the cavity. We characterize the imperfections of the photon generation and detection, including detection inefficiency and state infidelity caused by measurement back-action over a range of JPA gains from 17 to 33 dB. We observe that both detection efficiency and undesirable back-action increase with JPA gain. We find that the density matrix has its maximum single-photon component ρ11=0.36 ±0.01 at 29 dB JPA gain. At this gain, back-action of the JPA creates cavity photon number fluctuations that we model as a thermal distribution with an average photon number n ¯=0.041 ±0.003 .

  5. Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector

    NASA Technical Reports Server (NTRS)

    Huntington, Andrew

    2013-01-01

    The purpose of this program was to develop single-photon-sensitive short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode photon-counting APDs are desired for lidar because they have a shorter pixel dead time than Geiger APDs, and can detect sequential pulse returns from multiple objects that are closely spaced in range. Linear-mode APDs can also measure photon number, which Geiger APDs cannot, adding an extra dimension to lidar scene data for multi-photon returns. High-gain APDs with low multiplication noise are required for efficient linear-mode detection of single photons because of APD gain statistics -- a low-excess-noise APD will generate detectible current pulses from single photon input at a much higher rate of occurrence than will a noisy APD operated at the same average gain. MWIR and LWIR electron-avalanche HgCdTe APDs have been shown to operate in linear mode at high average avalanche gain (M > 1000) without excess multiplication noise (F = 1), and are therefore very good candidates for linear-mode photon counting. However, detectors fashioned from these narrow-bandgap alloys require aggressive cooling to control thermal dark current. Wider-bandgap SWIR HgCdTe APDs were investigated in this program as a strategy to reduce detector cooling requirements.

  6. In-depth study of single photon time resolution for the Philips digital silicon photomultiplier

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Gundacker, S.; Pizzichemi, M.; Ghezzi, A.; Auffray, E.; Lecoq, P.; Paganoni, M.

    2016-06-01

    The digital silicon photomultiplier (SiPM) has been commercialised by Philips as an innovative technology compared to analog silicon photomultiplier devices. The Philips digital SiPM, has a pair of time to digital converters (TDCs) connected to 12800 single photon avalanche diodes (SPADs). Detailed measurements were performed to understand the low photon time response of the Philips digital SiPM. The single photon time resolution (SPTR) of every single SPAD in a pixel consisting of 3200 SPADs was measured and an average value of 85 ps full width at half maximum (FWHM) was observed. Each SPAD sends the signal to the TDC with different signal propagation time, resulting in a so called trigger network skew. This distribution of the trigger network skew for a pixel (3200 SPADs) has been measured and a variation of 50 ps FWHM was extracted. The SPTR of the whole pixel is the combination of SPAD jitter, trigger network skew, and the SPAD non-uniformity. The SPTR of a complete pixel was 103 ps FWHM at 3.3 V above breakdown voltage. Further, the effect of the crosstalk at a low photon level has been studied, with the two photon time resolution degrading if the events are a combination of detected (true) photons and crosstalk events. Finally, the time response to multiple photons was investigated.

  7. Single passband microwave photonic filter with wideband tunability and adjustable bandwidth.

    PubMed

    Chen, Tong; Yi, Xiaoke; Li, Liwei; Minasian, Robert

    2012-11-15

    A new and simple structure for a single passband microwave photonic filter is presented. It is based on using an electro-optical phase modulator and a tunable optical filter and only requires a single wavelength source and a single photodetector. Experimental results are presented that demonstrate a single passband, flat-top radio-frequency filter response without free spectral range limitations, along with the capability of tuning the center frequency and filter bandwidth independently. PMID:23164884

  8. Single-photon experiments with liquid crystals for quantum science and quantum engineering applications

    NASA Astrophysics Data System (ADS)

    Lukishova, Svetlana G.; Liapis, Andreas C.; Bissell, Luke J.; Gehring, George M.; Winkler, Justin M.; Boyd, Robert W.

    2015-03-01

    We present here our results on using liquid crystals in experiments with nonclassical light sources: (1) single-photon sources exhibiting antibunching (separation of all photons in time), which are key components for secure quantum communication systems, and (2) entangled photon source with photons exhibiting quantum interference in a Hong-Ou- Mandel interferometer. In the first part, cholesteric liquid crystal hosts were used to create definite circular polarization of antibunched photons emitted by nanocrystal quantum dots. If the photon has unknown polarization, filtering it through a polarizer to produce the desired polarization for quantum key distribution with bits based on polarization states of photons will reduce by half the efficiency of a quantum cryptography system. In the first part, we also provide our results on observation of a circular polarized microcavity resonance in nanocrystal quantum dot fluorescence in a 1-D chiral photonic bandgap cholesteric liquid crystal microcavity. In the second part of this paper with indistinguishable, time-entangled photons, we demonstrate our experimental results on simulating quantum-mechanical barrier tunnelling phenomena. A Hong-Ou-Mandel dip (quantum interference effect) is shifted when a phase change was introduced on the way of one of entangled photons in pair (one arm of the interferometer) by inserting in this arm an electrically controlled planar-aligned nematic liquid crystal layer between two prisms in the conditions close to a frustrated total internal reflection. By applying different AC-voltages to the planar-aligned nematic layer and changing its refractive index, we can obtain various conditions for incident photon propagation - from total reflection to total transmission. Measuring changes of tunnelling times of photon through this structure with femtosecond resolution permitted us to answer some unresolved questions in quantum-mechanical barrier tunnelling phenomena.

  9. Compact 32-channel time-resolved single-photon detection system

    NASA Astrophysics Data System (ADS)

    Cuccato, A.; Antonioli, S.; Gulinatti, A.; Labanca, I.; Rech, I.; Ghioni, M.

    2013-05-01

    Nowadays, many research fields like biology, chemistry, medicine and space technology rely on high sensitivity imaging instruments that allow to exploit modern measurement techniques; among these, Time-Correlated Single-Photon Counting (TCSPC) provides extremely high time resolution. Single-photon detectors play a key role in these advanced imaging systems, and in recent years Single-Photon Avalanche Diodes (SPADs) have become a valid alternative to Photo Multiplier Tubes (PMTs). Moreover scientific research has recently focused on single photon detector arrays, pushed by a growing demand for multichannel systems. In this scenario, we developed a compact, stand-alone, 32-channel system for time-resolved single-photon counting applications. The system core is represented by a 32×1 SPAD array built in custom technology, featuring high time resolution, high photon detection efficiency (> 45%) and low dark count rate. The SPAD avalanche signal is exported through an integrated inverter which is placed close to the photo detector, this way the avalanche event is detected with high time resolution while achieving negligible crosstalk between adjacent pixels. SPAD proper operation is guaranteed by a 32×1 mixed passive-active quenching circuit (AQC) array built in 0.18 μm HV-CMOS technology; its digital outputs are fed to an FPGA that performs on-board processing of photon counting information. On the contrary, photon timing information is directly extracted from the pixel array and exported in Current Mode Logic (CML) standard. Preliminary experiments have been carried out on the developed system, resulting in a high time resolution (< 60 ps FWHM) and mean dark count rate lower than 8500 counts/s at 25°C.

  10. Broadband frequency conversion and shaping of single photons emitted from a nonlinear cavity.

    PubMed

    McCutcheon, Murray W; Chang, Darrick E; Zhang, Yinan; Lukin, Mikhail D; Loncar, Marko

    2009-12-01

    Much recent effort has focused on coupling individual quantum emitters to optical microcavities in order to produce single photons on demand, enable single-photon optical switching, and implement functional nodes of a quantum network. Techniques to control the bandwidth and frequency of the outgoing single photons are of practical importance, allowing direct emission into telecommunications wavelengths and "hybrid" quantum networks incorporating different emitters. Here, we describe an integrated approach involving a quantum emitter coupled to a nonlinear optical resonator, in which the emission wavelength and pulse shape are controlled using the intra-cavity nonlinearity. Our scheme is general in nature, and demonstrates how the photonic environment of a quantum emitter can be tailored to determine the emission properties. As specific examples, we discuss a high Q-factor, TE-TM double-mode photonic crystal cavity design that allows for direct generation of single photons at telecom wavelengths (1425 nm) starting from an InAs/GaAs quantum dot with a 950 nm transition wavelength, and a scheme for direct optical coupling between such a quantum dot and a diamond nitrogen-vacancy center at 637 nm. PMID:20052195

  11. Single Photon Counting Detectors for Low Light Level Imaging Applications

    NASA Astrophysics Data System (ADS)

    Kolb, Kimberly

    2015-10-01

    This dissertation presents the current state-of-the-art of semiconductor-based photon counting detector technologies. HgCdTe linear-mode avalanche photodiodes (LM-APDs), silicon Geiger-mode avalanche photodiodes (GM-APDs), and electron-multiplying CCDs (EMCCDs) are compared via their present and future performance in various astronomy applications. LM-APDs are studied in theory, based on work done at the University of Hawaii. EMCCDs are studied in theory and experimentally, with a device at NASA's Jet Propulsion Lab. The emphasis of the research is on GM-APD imaging arrays, developed at MIT Lincoln Laboratory and tested at the RIT Center for Detectors. The GM-APD research includes a theoretical analysis of SNR and various performance metrics, including dark count rate, afterpulsing, photon detection efficiency, and intrapixel sensitivity. The effects of radiation damage on the GM-APD were also characterized by introducing a cumulative dose of 50 krad(Si) via 60 MeV protons. Extensive development of Monte Carlo simulations and practical observation simulations was completed, including simulated astronomical imaging and adaptive optics wavefront sensing. Based on theoretical models and experimental testing, both the current state-of-the-art performance and projected future performance of each detector are compared for various applications. LM-APD performance is currently not competitive with other photon counting technologies, and are left out of the application-based comparisons. In the current state-of-the-art, EMCCDs in photon counting mode out-perform GM-APDs for long exposure scenarios, though GM-APDs are better for short exposure scenarios (fast readout) due to clock-induced-charge (CIC) in EMCCDs. In the long term, small improvements in GM-APD dark current will make them superior in both long and short exposure scenarios for extremely low flux. The efficiency of GM-APDs will likely always be less than EMCCDs, however, which is particularly disadvantageous for

  12. Simplified quantum bit commitment using single photon nonlocality

    NASA Astrophysics Data System (ADS)

    He, Guang Ping

    2014-10-01

    We simplified our previously proposed quantum bit commitment (QBC) protocol based on the Mach-Zehnder interferometer, by replacing symmetric beam splitters with asymmetric ones. It eliminates the need for random sending time of the photons; thus, the feasibility and efficiency are both improved. The protocol is immune to the cheating strategy in the Mayers-Lo-Chau no-go theorem of unconditionally secure QBC, because the density matrices of the committed states do not satisfy a crucial condition on which the no-go theorem holds.

  13. Nano-optical observation of cascade switching in a parallel superconducting nanowire single photon detector

    SciTech Connect

    Heath, Robert M. Tanner, Michael G.; Casaburi, Alessandro; Hadfield, Robert H.; Webster, Mark G.; San Emeterio Alvarez, Lara; Jiang, Weitao; Barber, Zoe H.; Warburton, Richard J.

    2014-02-10

    The device physics of parallel-wire superconducting nanowire single photon detectors is based on a cascade process. Using nano-optical techniques and a parallel wire device with spatially separate pixels, we explicitly demonstrate the single- and multi-photon triggering regimes. We develop a model for describing efficiency of a detector operating in the arm-trigger regime. We investigate the timing response of the detector when illuminating a single pixel and two pixels. We see a change in the active area of the detector between the two regimes and find the two-pixel trigger regime to have a faster timing response than the one-pixel regime.

  14. Single-photon multiple ionization forming double vacancies in the 2p subshell of argon

    NASA Astrophysics Data System (ADS)

    Linusson, P.; Fritzsche, S.; Eland, J. H. D.; Mucke, M.; Feifel, R.

    2013-04-01

    Single-photon ionization leading to two vacancies in the 2p subshell of argon is investigated experimentally using the photoelectron time-of-flight magnetic bottle coincidence technique. Three peaks corresponding to the 3P, 1D, and 1S states of the dication are found in the ionization energy range 535 to 562 eV. Multiconfigurational Dirac-Fock calculations were performed to estimate the single-photon double-ionization cross sections. Reasonable agreement between the measured and simulated spectra is found if single and double excitations are taken into account in the wave-function expansion.

  15. Observation of Entanglement of a Single Photon with a Trapped Atom

    SciTech Connect

    Volz, Juergen; Weber, Markus; Schlenk, Daniel; Rosenfeld, Wenjamin; Vrana, Johannes; Saucke, Karen; Kurtsiefer, Christian; Weinfurter, Harald

    2006-01-27

    We report the observation of entanglement between a single trapped atom and a single photon at a wavelength suitable for low-loss communication over large distances, thereby achieving a crucial step towards long range quantum networks. To verify the entanglement, we introduce a single atom state analysis. This technique is used for full state tomography of the atom-photon qubit pair. The detection efficiency and the entanglement fidelity are high enough to allow in a next step the generation of entangled atoms at large distances, ready for a final loophole-free Bell experiment.

  16. Single photon emission from site-controlled InGaN/GaN quantum dots

    SciTech Connect

    Zhang, Lei; Hill, Tyler A.; Deng, Hui; Teng, Chu-Hsiang; Lee, Leung-Kway; Ku, Pei-Cheng

    2013-11-04

    Single photon emission was observed from site-controlled InGaN/GaN quantum dots. The single-photon nature of the emission was verified by the second-order correlation function up to 90 K, the highest temperature to date for site-controlled quantum dots. Micro-photoluminescence study on individual quantum dots showed linearly polarized single exciton emission with a lifetime of a few nanoseconds. The dimensions of these quantum dots were well controlled to the precision of state-of-the-art fabrication technologies, as reflected in the uniformity of their optical properties. The yield of optically active quantum dots was greater than 90%, among which 13%–25% exhibited single photon emission at 10 K.

  17. Memory effect in silicon time-gated single-photon avalanche diodes

    SciTech Connect

    Dalla Mora, A.; Contini, D. Di Sieno, L.; Tosi, A.; Boso, G.; Villa, F.; Pifferi, A.

    2015-03-21

    We present a comprehensive characterization of the memory effect arising in thin-junction silicon Single-Photon Avalanche Diodes (SPADs) when exposed to strong illumination. This partially unknown afterpulsing-like noise represents the main limiting factor when time-gated acquisitions are exploited to increase the measurement dynamic range of very fast (picosecond scale) and faint (single-photon) optical signals following a strong stray one. We report the dependences of this unwelcome signal-related noise on photon wavelength, detector temperature, and biasing conditions. Our results suggest that this so-called “memory effect” is generated in the deep regions of the detector, well below the depleted region, and its contribution on detector response is visible only when time-gated SPADs are exploited to reject a strong burst of photons.

  18. Efficient single photon source based on μ-fibre-coupled tunable microcavity

    PubMed Central

    Lee, Chang-Min; Lim, Hee-Jin; Schneider, Christian; Maier, Sebastian; Höfling, Sven; Kamp, Martin; Lee, Yong-Hee

    2015-01-01

    Efficient and fast on-demand single photon sources have been sought after as critical components of quantum information science. We report an efficient and tunable single photon source based on an InAs quantum dot (QD) embedded in a photonic crystal cavity coupled with a highly curved μ-fibre. Exploiting evanescent coupling between the μ-fibre and the cavity, a high collection efficiency of 23% and Purcell-enhanced spontaneous emissions are observed. In our scheme, the spectral position of a resonance can be tuned by as much as 1.5 nm by adjusting the contact position of the μ-fibre, which increases the spectral coupling probability between the QD and the cavity mode. Taking advantage of the high photon count rate and the tunability, the collection efficiencies and the decay rates are systematically investigated as a function of the QD–cavity detuning. PMID:26391607

  19. Efficient single photon source based on μ-fibre-coupled tunable microcavity.

    PubMed

    Lee, Chang-Min; Lim, Hee-Jin; Schneider, Christian; Maier, Sebastian; Höfling, Sven; Kamp, Martin; Lee, Yong-Hee

    2015-01-01

    Efficient and fast on-demand single photon sources have been sought after as critical components of quantum information science. We report an efficient and tunable single photon source based on an InAs quantum dot (QD) embedded in a photonic crystal cavity coupled with a highly curved μ-fibre. Exploiting evanescent coupling between the μ-fibre and the cavity, a high collection efficiency of 23% and Purcell-enhanced spontaneous emissions are observed. In our scheme, the spectral position of a resonance can be tuned by as much as 1.5 nm by adjusting the contact position of the μ-fibre, which increases the spectral coupling probability between the QD and the cavity mode. Taking advantage of the high photon count rate and the tunability, the collection efficiencies and the decay rates are systematically investigated as a function of the QD-cavity detuning. PMID:26391607

  20. Remote preparation of single-photon "hybrid" entangled and vector-polarization States.

    PubMed

    Barreiro, Julio T; Wei, Tzu-Chieh; Kwiat, Paul G

    2010-07-16

    Quantum teleportation faces increasingly demanding requirements for transmitting large or even entangled systems. However, knowledge of the state to be transmitted eases its reconstruction, resulting in a protocol known as remote state preparation. A number of experimental demonstrations to date have been restricted to single-qubit systems. We report the remote preparation of two-qubit "hybrid" entangled states, including a family of vector-polarization beams. Our single-photon states are encoded in the photon spin and orbital angular momentum. We reconstruct the states by spin-orbit state tomography and transverse polarization tomography. The high fidelities achieved for the vector-polarization states opens the door to optimal coupling of down-converted photons to other physical systems, such as an atom, as required for scalable quantum networks, or plasmons in photonic nanostructures. PMID:20867752

  1. Photon-statistics-based classical ghost imaging with one single detector.

    PubMed

    Kuhn, Simone; Hartmann, Sébastien; Elsäßer, Wolfgang

    2016-06-15

    We demonstrate a novel ghost imaging (GI) scheme based on one single-photon-counting detector with subsequent photon statistics analysis. The key idea is that instead of measuring correlations between the object and reference beams such as in standard GI schemes, the light of the two beams is superimposed. The photon statistics analysis of this mixed light allows us to determine the photon number distribution as well as to calculate the central second-order correlation coefficient. The image information is obtained as a function of the spatial resolution of the reference beam. The performance of this photon-statistics-based GI system with one single detector (PS-GI) is investigated in terms of visibility and resolution. Finally, the knowledge of the complete photon statistics allows easy access to higher correlation coefficients such that we are able to perform here third- and fourth-order GI. The PS-GI concept can be seen as a complement to already existing GI technologies thus enabling a broader dissemination of GI as a superior metrology technique, paving the road for new applications in particular with advanced photon counting detectors. PMID:27304308

  2. Microwave-Controlled Generation of Shaped Single Photons in Circuit Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Pechal, M.; Huthmacher, L.; Eichler, C.; Zeytinoǧlu, S.; Abdumalikov, A. A.; Berger, S.; Wallraff, A.; Filipp, S.

    2014-10-01

    Large-scale quantum information processors or quantum communication networks will require reliable exchange of information between spatially separated nodes. The links connecting these nodes can be established using traveling photons that need to be absorbed at the receiving node with high efficiency. This is achievable by shaping the temporal profile of the photons and absorbing them at the receiver by time reversing the emission process. Here, we demonstrate a scheme for creating shaped microwave photons using a superconducting transmon-type three-level system coupled to a transmission line resonator. In a second-order process induced by a modulated microwave drive, we controllably transfer a single excitation from the third level of the transmon to the resonator and shape the emitted photon. We reconstruct the density matrices of the created single-photon states and show that the photons are antibunched. We also create multipeaked photons with a controlled amplitude and phase. In contrast to similar existing schemes, the one we present here is based solely on microwave drives, enabling operation with fixed frequency transmons.

  3. Single photon avalanche detectors: prospects of new quenching and gain mechanisms

    NASA Astrophysics Data System (ADS)

    Hall, David; Liu, Yu-Hsin; Lo, Yu-Hwa

    2015-11-01

    While silicon single-photon avalanche diodes (SPAD) have reached very high detection efficiency and timing resolution, their use in fibre-optic communications, optical free space communications, and infrared sensing and imaging remains limited. III-V compounds including InGaAs and InP are the prevalent materials for 1550 nm light detection. However, even the most sensitive 1550 nm photoreceivers in optical communication have a sensitivity limit of a few hundred photons. Today, the only viable approach to achieve single-photon sensitivity at 1550 nm wavelength from semiconductor devices is to operate the avalanche detectors in Geiger mode, essentially trading dynamic range and speed for sensitivity. As material properties limit the performance of Ge and III-V detectors, new conceptual insight with regard to novel quenching and gain mechanisms could potentially address the performance limitations of III-V SPADs. Novel designs that utilise internal self-quenching and negative feedback can be used to harness the sensitivity of single-photon detectors,while drastically reducing the device complexity and increasing the level of integration. Incorporation of multiple gain mechanisms, together with self-quenching and built-in negative feedback, into a single device also hold promise for a new type of detector with single-photon sensitivity and large dynamic range.

  4. Rise time of voltage pulses in NbN superconducting single photon detectors

    NASA Astrophysics Data System (ADS)

    Smirnov, K. V.; Divochiy, A. V.; Vakhtomin, Yu. B.; Sidorova, M. V.; Karpova, U. V.; Morozov, P. V.; Seleznev, V. A.; Zotova, A. N.; Vodolazov, D. Yu.

    2016-08-01

    We have found experimentally that the rise time of voltage pulse in NbN superconducting single photon detectors increases nonlinearly with increasing the length of the detector L. The effect is connected with dependence of resistance of the detector Rn, which appears after photon absorption, on its kinetic inductance Lk and, hence, on the length of the detector. This conclusion is confirmed by our calculations in the framework of two temperature model.

  5. Experimental realization of macroscopic coherence by phase-covariant cloning of a single photon

    SciTech Connect

    Nagali, Eleonora; De Angelis, Tiziano; De Martini, Francesco; Sciarrino, Fabio

    2007-10-15

    We investigate the multiphoton states generated by high-gain optical parametric amplification of a single injected photon, polarization encoded as a 'qubit'. The experiment configuration exploits the optimal phase-covariant cloning in the high gain regime. The interference fringe pattern showing the nonlocal transfer of coherence between the injected qubit and the mesoscopic amplified output field involving up to 4000 photons has been investigated. A probabilistic method to extract full information about the multiparticle output wave function has been implemented.

  6. High quality GaAs single photon emitters on Si substrate

    SciTech Connect

    Bietti, S.; Sanguinetti, S.; Cavigli, L.; Accanto, N.; Vinattieri, A.; Minari, S.; Abbarchi, M.; Isella, G.; Frigeri, C.

    2013-12-04

    We describe a method for the direct epitaxial growth of a single photon emitter, based on GaAs quantum dots fabricated by droplet epitaxy, working at liquid nitrogen temperatures on Si substrates. The achievement of quantum photon statistics up to T=80 K is directly proved by antibunching in the second order correlation function as measured with a H anbury Brown and Twiss interferometer.

  7. Single-spin asymmetries from two-photon exchange in elastic electron proton scattering

    SciTech Connect

    A.V. Afanasev; N.P. Merenkov

    2005-02-01

    The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. An optical theorem is used to evaluate the asymmetry in terms of the total photoproduction cross section on the proton.

  8. Polarization dependence of the phase of interference between single- and two-photon ionization.

    PubMed

    Baranova, N B; Chudinov, A N; Shulginov, A A; Zel'dovich, B Y

    1991-09-01

    The interference between single-photon and two-photon ionization has been observed for electrons ejected in the direction n from the photomultiplier cathode exposed simultaneously to the picosecond pulse of a Nd laser E(omega) and its second harmonic E(2omega). The change of the phase difference of such interference was measured for the switch of the polarizations from E(omega) ||n, E(2omega) ||n to E(omega) ? n, E(2omega) || n. PMID:19776966

  9. Interfacing GHz-bandwidth heralded single photons with a warm vapour Raman memory

    NASA Astrophysics Data System (ADS)

    Michelberger, P. S.; Champion, T. F. M.; Sprague, M. R.; Kaczmarek, K. T.; Barbieri, M.; Jin, X. M.; England, D. G.; Kolthammer, W. S.; Saunders, D. J.; Nunn, J.; Walmsley, I. A.

    2015-04-01

    Broadband quantum memories, used as temporal multiplexers, are a key component in photonic quantum information processing, as they make repeat-until-success strategies scalable. We demonstrate a prototype system, operating on-demand, by interfacing a warm vapour, high time-bandwidth-product Raman memory with a travelling wave spontaneous parametric down-conversion source. We store single photons and observe a clear influence of the input photon statistics on the retrieved light, which we find currently to be limited by noise. We develop a theoretical model that identifies four-wave mixing as the sole important noise source and point towards practical solutions for noise-free operation.

  10. Channel analysis for single photon underwater free space quantum key distribution.

    PubMed

    Shi, Peng; Zhao, Shi-Cheng; Gu, Yong-Jian; Li, Wen-Dong

    2015-03-01

    We investigate the optical absorption and scattering properties of underwater media pertinent to our underwater free space quantum key distribution (QKD) channel model. With the vector radiative transfer theory and Monte Carlo method, we obtain the attenuation of photons, the fidelity of the scattered photons, the quantum bit error rate, and the sifted key generation rate of underwater quantum communication. It can be observed from our simulations that the most secure single photon underwater free space QKD is feasible in the clearest ocean water. PMID:26366645

  11. Optical time domain reflectometry with low noise waveguide-coupled superconducting nanowire single-photon detectors

    NASA Astrophysics Data System (ADS)

    Schuck, C.; Pernice, W. H. P.; Ma, X.; Tang, H. X.

    2013-05-01

    We demonstrate optical time domain reflectometry over 200 km of optical fiber using low-noise NbTiN superconducting single-photon detectors integrated with Si3N4 waveguides. Our small detector footprint enables high timing resolution of 50 ps and a dark count rate of 3 Hz with unshielded fibers, allowing for identification of defects along the fiber over a dynamic range of 37.4 dB. Photons scattered and reflected back from the fiber under test can be detected in free-running mode without showing dead zones or other impairments often encountered in semiconductor photon-counting optical time domain reflectometers.

  12. Heralded single-photon source from spontaneous four-wave mixing process in lossy waveguides

    NASA Astrophysics Data System (ADS)

    Silva, Nuno A.; Pinto, Armando N.

    2015-10-01

    We investigate theoretically the spontaneous four-wave mixing (FWM) process that occurs in optical waveguides, as a source of quantum correlated photon-pairs. We consider that the waveguide used to implement the spontaneous FWM process presents a high value of nonlinear parameter, γ = 93.4 W-1m-1, and a non-negligible value of loss coefficient, α = 133.3 dB/m. Moreover, the theoretical model also consider the Raman scattering that inevitably accompanies the FWM process, and generates time-uncorrelated (noise) photon pairs. We use the coincident-to-accidental ratio (CAR) as a figure of merit of the photon pair source, and we were able to observe a CAR of the order of 65 in a high loss regime. After, we use the time-correlated photon pairs generated by the spontaneous FWM process to implement a heralded single photon source at waveguide output. In this scenario, the detection of one photon of the pair heralds the presence of the other photon. The quality of the source was studied by the evaluation of the second order coherence function for one photon of the pair conditioned by the detection of its twin photon. We observe that the presence of a high loss coefficient tends to improve the quality of the photon source, when compared with the lossless regime, even considering the Raman noise photons. We obtain a value for the conditional second order coherence function of the order of 0.11 in absence of loss, and a value of 0.03 for a loss coefficient of 133.3 dB/m.

  13. A cascade of e ‑ e + pair production by a photon with subsequent annihilation to a single photon in a strong magnetic field

    NASA Astrophysics Data System (ADS)

    Diachenko, M. M.; Novak, O. P.; Kholodov, R. I.

    2016-06-01

    The process of electron–positron pair production by a photon with subsequent annihilation to a single photon in a strong magnetic field has been studied. The general amplitude has been calculated and the process rates have been found in a low Landau levels approximation (resonant and nonresonant cases). The comparison of resonant and nonresonant cases shows a significant excess of the resonant rate. The polarization of the final photon in a strong magnetic field has also been found. It has been shown that polarizations of the initial and final photons are independent except for the case of normal linear polarization of the initial photon.

  14. Quantum Interference Induced Photon Blockade in a Coupled Single Quantum Dot-Cavity System

    PubMed Central

    Tang, Jing; Geng, Weidong; Xu, Xiulai

    2015-01-01

    We propose an experimental scheme to implement a strong photon blockade with a single quantum dot coupled to a nanocavity. The photon blockade effect can be tremendously enhanced by driving the cavity and the quantum dot simultaneously with two classical laser fields. This enhancement of photon blockade is ascribed to the quantum interference effect to avoid two-photon excitation of the cavity field. Comparing with Jaynes-Cummings model, the second-order correlation function at zero time delay g(2)(0) in our scheme can be reduced by two orders of magnitude and the system sustains a large intracavity photon number. A red (blue) cavity-light detuning asymmetry for photon quantum statistics with bunching or antibunching characteristics is also observed. The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field. Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system. This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing. PMID:25783560

  15. Reduced-Density-Matrix Description of Single-Photon and Multi-Photon Processes in Quantized Many-Electron Systems

    NASA Astrophysics Data System (ADS)

    Jacobs, Verne; Kutana, Alex

    The frequency-dependent transition rates for single-photon and multi-photon processes in quantized many-electron systems are evaluated using a reduced-density-matrix approach. We provide a fundamental quantum-mechanical foundation for systematic spectral simulations. A perturbation expansion of the frequency-domain Liouville-space self-energy operator is introduced for detailed evaluations of the spectral-line shapes. In the diagonal-resolvent (isolated-line) and short-memory-time (Markov) approximations, the lowest-order contributions to the spectral-line widths and shifts associated with environmental electron-photon and electron-phonon interactions are systematically evaluated. Our description is directly applicable to electromagnetic processes in a wide variety of many-electron systems, without premature approximations. In particular, our approach can be applied to investigate quantum optical phenomena involving electrons in both bulk and nanoscale semiconductor materials entirely from first principles, using a single-electron basis set obtained from density functional theory as a starting point for a many-electron description. Work supported by the Office of Naval Research through the Basic Research Program at The Naval Research Laboratory. A portion of this work was performed under the ASEE post doc program at NRL.

  16. High-speed bridge circuit for InGaAs avalanche photodiode single-photon detector

    NASA Astrophysics Data System (ADS)

    Hashimoto, Hirofumi; Tomita, Akihisa; Okamoto, Atsushi

    2014-02-01

    Because of low power consumption and small footprint, avalanche photodiodes (APD) have been commonly applied to photon detection. Recently, high speed quantum communication has been demonstrated for high bit-rate quantum key distribution. For the high speed quantum communication, photon detectors should operate at GHz-clock frequencies. We propose balanced detection circuits for GHz-clock operation of InGaAs-APD photon detectors. The balanced single photon detector operates with sinusoidal wave gating. The sinusoidal wave appearing in the output is removed by the subtraction from APD signal without sharp band-elimination filters. Omission of the sharp filters removes the constraint on the operating frequency of the single photon detector. We present two designs, one works with two identical APDs, the other with one APD and a low-pass filter. The sinusoidal gating enables to eliminate the gating noise even with the simple configuration of the latter design. We demonstrated the balanced single photon detector operating with 1.020GHz clock at 233 K, 193 K, and 186.5 K. The dark count probability was 4.0 x 10-4 counts/pulse with the quantum efficiency of 10% at 233K, and 1.6 x 10-4 counts/pulse at 186.5 K. These results were obtained with easily available APDs (NR8300FP-C.C, RENESASS) originally developed for optical time-domain reflectmeters.

  17. High-speed and high-efficiency travelling wave single-photon detectors embedded in nanophotonic circuits

    PubMed Central

    Pernice, W.H.P.; Schuck, C.; Minaeva, O.; Li, M.; Goltsman, G.N.; Sergienko, A.V.; Tang, H.X.

    2012-01-01

    Ultrafast, high-efficiency single-photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. However, imperfect modal matching and finite photon absorption rates have usually limited their maximum attainable detection efficiency. Here we demonstrate superconducting nanowire detectors atop nanophotonic waveguides, which enable a drastic increase of the absorption length for incoming photons. This allows us to achieve high on-chip single-photon detection efficiency up to 91% at telecom wavelengths, repeatable across several fabricated chips. We also observe remarkably low dark count rates without significant compromise of the on-chip detection efficiency. The detectors are fully embedded in scalable silicon photonic circuits and provide ultrashort timing jitter of 18 ps. Exploiting this high temporal resolution, we demonstrate ballistic photon transport in silicon ring resonators. Our direct implementation of a high-performance single-photon detector on chip overcomes a major barrier in integrated quantum photonics. PMID:23271658

  18. A universal setup for active control of a single-photon detector

    NASA Astrophysics Data System (ADS)

    Liu, Qin; Lamas-Linares, Antía; Kurtsiefer, Christian; Skaar, Johannes; Makarov, Vadim; Gerhardt, Ilja

    2014-01-01

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.

  19. Near-Transform-Limited Single Photons from an Efficient Solid-State Quantum Emitter.

    PubMed

    Wang, Hui; Duan, Z-C; Li, Y-H; Chen, Si; Li, J-P; He, Y-M; Chen, M-C; He, Yu; Ding, X; Peng, Cheng-Zhi; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2016-05-27

    By pulsed s-shell resonant excitation of a single quantum dot-micropillar system, we generate long streams of 1000 near-transform-limited single photons with high mutual indistinguishability. The Hong-Ou-Mandel interference of two photons is measured as a function of their emission time separation varying from 13 ns to 14.7  μs, where the visibility slightly drops from 95.9(2)% to a plateau of 92.1(5)% through a slow dephasing process occurring at a time scale of 0.7  μs. A temporal and spectral analysis reveals the pulsed resonance fluorescence single photons are close to the transform limit, which are readily useful for multiphoton entanglement and interferometry experiments. PMID:27284656

  20. Characterization of NbN films for superconducting nanowire single photon detectors

    SciTech Connect

    Mcdonald, Ross D; Ayala - Valenzuela, Oscar E; Weisse - Bernstein, Nina R; Williamson, Todd L; Hoffbauer, M. A.; Graf, M. J.; Rabin, M. W.

    2011-01-14

    Nanoscopic superconducting meander patterns offer great promise as a new class of cryogenic radiation sensors capable of single photon detection. To realize this potential, control of the superconducting properties on the nanoscale is imperative. To this end, Superconducting Nanowire Single Photon Detectors (SNSPDs) are under development by means Energetic Neutral Atom Beam Lithography and Epitaxy, or ENABLE. ENABLE can growth highly-crystalline, epitaxial thin-film materials, like NbN, at low temperatures; such wide-ranging control of fabrication parameters is enabling the optimization of film properties for single photon detection. T{sub c}, H{sub c2}, {zeta}{sub GL} and J{sub c} of multiple thin films and devices have been studied as a function of growth conditions. The optimization of which has already produced devices with properties rivaling all reports in the existing literature.

  1. Generation, transmission, and detection of terahertz photons on an electrically driven single chip

    SciTech Connect

    Ikushima, Kenji; Ito, Atsushi; Okano, Shun

    2014-02-03

    We demonstrate single photon counting of terahertz (THz) waves transmitted from a local THz point source through a coplanar two-wire waveguide on a GaAs/AlGaAs single heterostructure crystal. In the electrically driven all-in-one chip, quantum Hall edge transport is used to achieve a noiseless injection current for a monochromatic point source of THz fields. The local THz fields are coupled to a coplanar two-wire metal waveguide and transmitted over a macroscopic scale greater than the wavelength (38 μm in GaAs). THz waves propagating on the waveguide are counted as individual photons by a quantum-dot single-electron transistor on the same chip. Photon counting on integrated high-frequency circuits will open the possibilities for on-chip quantum optical experiments.

  2. A universal setup for active control of a single-photon detector

    SciTech Connect

    Liu, Qin; Skaar, Johannes; Lamas-Linares, Antía; Kurtsiefer, Christian; Makarov, Vadim; Gerhardt, Ilja

    2014-01-15

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.

  3. A universal setup for active control of a single-photon detector.

    PubMed

    Liu, Qin; Lamas-Linares, Antía; Kurtsiefer, Christian; Skaar, Johannes; Makarov, Vadim; Gerhardt, Ilja

    2014-01-01

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors. PMID:24517746

  4. Stable single-mode operation of surface-emitting terahertz lasers with graded photonic heterostructure resonators

    NASA Astrophysics Data System (ADS)

    Xu, Gangyi; Halioua, Yacine; Moumdji, Souad; Colombelli, Raffaele; Beere, Harvey E.; Ritchie, David A.

    2013-06-01

    Graded photonic heterostructures (GPH) can be regarded as energy wells for photons. We show that judicious engineering of such photonic wells, obtained by tailoring the grading and the slit width of the GPH resonator, allows one to ensure spectrally single-mode emission on the fundamental symmetric mode in the whole lasing dynamical range of terahertz quantum cascade lasers. Furthermore, the radiative character of the symmetric mode leads to single-mode emission with mW output power in continuous-wave operation, as well as to single-lobed far-field beam patterns. A careful combination of theoretical analysis and experimental observations reveals that the results stem from interplay between mode competition and spatial hole burning effects.

  5. Reconfigurable Computing As an Enabling Technology for Single-Photon-Counting Laser Altimetry

    NASA Technical Reports Server (NTRS)

    Powell, Wesley; Hicks, Edward; Pinchinat, Maxime; Dabney, Philip; McGarry, Jan; Murray, Paul

    2003-01-01

    Single-photon-counting laser altimetry is a new measurement technique offering significant advantages in vertical resolution, reducing instrument size, mass, and power, and reducing laser complexity as compared to analog or threshold detection laser altimetry techniques. However, these improvements come at the cost of a dramatically increased requirement for onboard real-time data processing. Reconfigurable computing has been shown to offer considerable performance advantages in performing this processing. These advantages have been demonstrated on the Multi-KiloHertz Micro-Laser Altimeter (MMLA), an aircraft based single-photon-counting laser altimeter developed by NASA Goddard Space Flight Center with several potential spaceflight applications. This paper describes how reconfigurable computing technology was employed to perform MMLA data processing in real-time under realistic operating constraints, along with the results observed. This paper also expands on these prior results to identify concepts for using reconfigurable computing to enable spaceflight single-photon-counting laser altimeter instruments.

  6. 0.5 billion events per second time correlated single photon counting using CMOS SPAD arrays.

    PubMed

    Krstajić, Nikola; Poland, Simon; Levitt, James; Walker, Richard; Erdogan, Ahmet; Ameer-Beg, Simon; Henderson, Robert K

    2015-09-15

    We present a digital architecture for fast acquisition of time correlated single photon counting (TCSPC) events from a 32×32 complementary metal oxide semiconductor (CMOS) single photon avalanche detector (SPAD) array (Megaframe) to the computer memory. Custom firmware was written to transmit event codes from 1024-TCSPC-enabled pixels for fast transfer of TCSPC events. Our 1024-channel TCSPC system is capable of acquiring up to 0.5×10(9) TCSPC events per second with 16 histogram bins spanning a 14 ns width. Other options include 320×10(6) TCSPC events per second with 256 histogram bins spanning either a 14 or 56 ns time window. We present a wide-field fluorescence microscopy setup demonstrating fast fluorescence lifetime data acquisition. To the best of our knowledge, this is the fastest direct TCSPC transfer from a single photon counting device to the computer to date. PMID:26371922

  7. Generating single photons at gigahertz modulation-speed using electrically controlled quantum dot microlenses

    NASA Astrophysics Data System (ADS)

    Schlehahn, A.; Schmidt, R.; Hopfmann, C.; Schulze, J.-H.; Strittmatter, A.; Heindel, T.; Gantz, L.; Schmidgall, E. R.; Gershoni, D.; Reitzenstein, S.

    2016-01-01

    We report on the generation of single-photon pulse trains at a repetition rate of up to 1 GHz. We achieve this speed by modulating the external voltage applied on an electrically contacted quantum dot microlens, which is optically excited by a continuous-wave laser. By modulating the photoluminescence of the quantum dot microlens using a square-wave voltage, single-photon emission is triggered with a response time as short as (281 ± 19) ps, being 6 times faster than the radiative lifetime of (1.75 ± 0.02) ns. This large reduction in the characteristic emission time is enabled by a rapid capacitive gating of emission from the quantum dot, which is placed in the intrinsic region of a p-i-n-junction biased below the onset of electroluminescence. Here, since our circuit acts as a rectifying differentiator, the rising edge of the applied voltage pulses triggers the emission of single photons from the optically excited quantum dot. The non-classical nature of the photon pulse train generated at GHz-speed is proven by intensity autocorrelation measurements with g(2)(0) = 0.3 ± 0.1. Our results combine optical excitation with fast electrical gating and thus show promise for the generation of indistinguishable single photons at rates exceeding the limitations set by the intrinsic radiative lifetime.

  8. A study of pile-up in integrated time-correlated single photon counting systems.

    PubMed

    Arlt, Jochen; Tyndall, David; Rae, Bruce R; Li, David D-U; Richardson, Justin A; Henderson, Robert K

    2013-10-01

    Recent demonstration of highly integrated, solid-state, time-correlated single photon counting (TCSPC) systems in CMOS technology is set to provide significant increases in performance over existing bulky, expensive hardware. Arrays of single photon single photon avalanche diode (SPAD) detectors, timing channels, and signal processing can be integrated on a single silicon chip with a degree of parallelism and computational speed that is unattainable by discrete photomultiplier tube and photon counting card solutions. New multi-channel, multi-detector TCSPC sensor architectures with greatly enhanced throughput due to minimal detector transit (dead) time or timing channel dead time are now feasible. In this paper, we study the potential for future integrated, solid-state TCSPC sensors to exceed the photon pile-up limit through analytic formula and simulation. The results are validated using a 10% fill factor SPAD array and an 8-channel, 52 ps resolution time-to-digital conversion architecture with embedded lifetime estimation. It is demonstrated that pile-up insensitive acquisition is attainable at greater than 10 times the pulse repetition rate providing over 60 dB of extended dynamic range to the TCSPC technique. Our results predict future CMOS TCSPC sensors capable of live-cell transient observations in confocal scanning microscopy, improved resolution of near-infrared optical tomography systems, and fluorescence lifetime activated cell sorting. PMID:24182099

  9. Single microwave-photon detector using an artificial Λ-type three-level system.

    PubMed

    Inomata, Kunihiro; Lin, Zhirong; Koshino, Kazuki; Oliver, William D; Tsai, Jaw-Shen; Yamamoto, Tsuyoshi; Nakamura, Yasunobu

    2016-01-01

    Single-photon detection is a requisite technique in quantum-optics experiments in both the optical and the microwave domains. However, the energy of microwave quanta are four to five orders of magnitude less than their optical counterpart, making the efficient detection of single microwave photons extremely challenging. Here we demonstrate the detection of a single microwave photon propagating through a waveguide. The detector is implemented with an impedance-matched artificial Λ system comprising the dressed states of a driven superconducting qubit coupled to a microwave resonator. Each signal photon deterministically induces a Raman transition in the Λ system and excites the qubit. The subsequent dispersive readout of the qubit produces a discrete 'click'. We attain a high single-photon-detection efficiency of 0.66±0.06 with a low dark-count probability of 0.014±0.001 and a reset time of ∼400 ns. This detector can be exploited for various applications in quantum sensing, quantum communication and quantum information processing. PMID:27453153

  10. Single microwave-photon detector using an artificial Λ-type three-level system

    PubMed Central

    Inomata, Kunihiro; Lin, Zhirong; Koshino, Kazuki; Oliver, William D.; Tsai, Jaw-Shen; Yamamoto, Tsuyoshi; Nakamura, Yasunobu

    2016-01-01

    Single-photon detection is a requisite technique in quantum-optics experiments in both the optical and the microwave domains. However, the energy of microwave quanta are four to five orders of magnitude less than their optical counterpart, making the efficient detection of single microwave photons extremely challenging. Here we demonstrate the detection of a single microwave photon propagating through a waveguide. The detector is implemented with an impedance-matched artificial Λ system comprising the dressed states of a driven superconducting qubit coupled to a microwave resonator. Each signal photon deterministically induces a Raman transition in the Λ system and excites the qubit. The subsequent dispersive readout of the qubit produces a discrete ‘click'. We attain a high single-photon-detection efficiency of 0.66±0.06 with a low dark-count probability of 0.014±0.001 and a reset time of ∼400 ns. This detector can be exploited for various applications in quantum sensing, quantum communication and quantum information processing. PMID:27453153

  11. A study of pile-up in integrated time-correlated single photon counting systems

    NASA Astrophysics Data System (ADS)

    Arlt, Jochen; Tyndall, David; Rae, Bruce R.; Li, David D.-U.; Richardson, Justin A.; Henderson, Robert K.

    2013-10-01

    Recent demonstration of highly integrated, solid-state, time-correlated single photon counting (TCSPC) systems in CMOS technology is set to provide significant increases in performance over existing bulky, expensive hardware. Arrays of single photon single photon avalanche diode (SPAD) detectors, timing channels, and signal processing can be integrated on a single silicon chip with a degree of parallelism and computational speed that is unattainable by discrete photomultiplier tube and photon counting card solutions. New multi-channel, multi-detector TCSPC sensor architectures with greatly enhanced throughput due to minimal detector transit (dead) time or timing channel dead time are now feasible. In this paper, we study the potential for future integrated, solid-state TCSPC sensors to exceed the photon pile-up limit through analytic formula and simulation. The results are validated using a 10% fill factor SPAD array and an 8-channel, 52 ps resolution time-to-digital conversion architecture with embedded lifetime estimation. It is demonstrated that pile-up insensitive acquisition is attainable at greater than 10 times the pulse repetition rate providing over 60 dB of extended dynamic range to the TCSPC technique. Our results predict future CMOS TCSPC sensors capable of live-cell transient observations in confocal scanning microscopy, improved resolution of near-infrared optical tomography systems, and fluorescence lifetime activated cell sorting.

  12. Single microwave-photon detector using an artificial Λ-type three-level system

    NASA Astrophysics Data System (ADS)

    Inomata, Kunihiro; Lin, Zhirong; Koshino, Kazuki; Oliver, William D.; Tsai, Jaw-Shen; Yamamoto, Tsuyoshi; Nakamura, Yasunobu

    2016-07-01

    Single-photon detection is a requisite technique in quantum-optics experiments in both the optical and the microwave domains. However, the energy of microwave quanta are four to five orders of magnitude less than their optical counterpart, making the efficient detection of single microwave photons extremely challenging. Here we demonstrate the detection of a single microwave photon propagating through a waveguide. The detector is implemented with an impedance-matched artificial Λ system comprising the dressed states of a driven superconducting qubit coupled to a microwave resonator. Each signal photon deterministically induces a Raman transition in the Λ system and excites the qubit. The subsequent dispersive readout of the qubit produces a discrete `click'. We attain a high single-photon-detection efficiency of 0.66+/-0.06 with a low dark-count probability of 0.014+/-0.001 and a reset time of ~400 ns. This detector can be exploited for various applications in quantum sensing, quantum communication and quantum information processing.

  13. Theoretical modeling of single-molecule fluorescence with complicated photon statistics

    NASA Astrophysics Data System (ADS)

    Osad'ko, I. S.; Naumov, A. V.; Eremchev, I. Yu.; Vainer, Yu. G.; Kador, L.

    2012-11-01

    The use of techniques for analyzing the fluorescence photon statistics of a single molecule for modeling single-emitter dynamics is demonstrated. The photon distribution function measured in the fluorescence of a single tetra-tert-butylterrylene molecule embedded in polyisobutylene is used to devise a theoretical model for single emitters with complicated fluorescence photon statistics. Our analysis was carried out with the theoretical approach developed by Osad'ko and co-workers [J. Chem. Phys.JCPSA60021-960610.1063/1.3055287 130, 064904 (2009); J. Phys. Chem. C10.1021/jp1014093 114, 10349 (2010)] for photon distribution functions. Although the experimental data were obtained at cryogenic temperature where narrow zero-phonon lines are present, the method is based on a purely statistical approach and does not require spectrally resolved data. It can also be applied to the analysis of broad fluorescence bands as measured at room temperature. Therefore, the method has prospects for revealing the quantum dynamics of single biological objects and other single quantum emitters in ambient conditions.

  14. A quantum gate between a flying optical photon and a single trapped atom.

    PubMed

    Reiserer, Andreas; Kalb, Norbert; Rempe, Gerhard; Ritter, Stephan

    2014-04-10

    The steady increase in control over individual quantum systems supports the promotion of a quantum technology that could provide functionalities beyond those of any classical device. Two particularly promising applications have been explored during the past decade: photon-based quantum communication, which guarantees unbreakable encryption but which still has to be scaled to high rates over large distances, and quantum computation, which will fundamentally enhance computability if it can be scaled to a large number of quantum bits (qubits). It was realized early on that a hybrid system of light qubits and matter qubits could solve the scalability problem of each field--that of communication by use of quantum repeaters, and that of computation by use of an optical interconnect between smaller quantum processors. To this end, the development of a robust two-qubit gate that allows the linking of distant computational nodes is "a pressing challenge". Here we demonstrate such a quantum gate between the spin state of a single trapped atom and the polarization state of an optical photon contained in a faint laser pulse. The gate mechanism presented is deterministic and robust, and is expected to be applicable to almost any matter qubit. It is based on reflection of the photonic qubit from a cavity that provides strong light-matter coupling. To demonstrate its versatility, we use the quantum gate to create atom-photon, atom-photon-photon and photon-photon entangled states from separable input states. We expect our experiment to enable various applications, including the generation of atomic and photonic cluster states and Schrödinger-cat states, deterministic photonic Bell-state measurements, scalable quantum computation and quantum communication using a redundant quantum parity code. PMID:24717512

  15. Experimental optimal maximum-confidence discrimination and optimal unambiguous discrimination of two mixed single-photon states

    SciTech Connect

    Steudle, Gesine A.; Knauer, Sebastian; Herzog, Ulrike; Benson, Oliver; Stock, Erik; Bimberg, Dieter; Haisler, Vladimir A.

    2011-05-15

    We present an experimental implementation of optimum measurements for quantum state discrimination. Optimum maximum-confidence discrimination and optimum unambiguous discrimination of two mixed single-photon polarization states were performed. For the latter the states of rank 2 in a four-dimensional Hilbert space are prepared using both path and polarization encoding. Linear optics and single photons from a true single-photon source based on a semiconductor quantum dot are utilized.

  16. Realizing quantum advantage without entanglement in single-photon states

    NASA Astrophysics Data System (ADS)

    Maldonado-Trapp, Alejandra; Solano, Pablo; Hu, Anzi; Clark, Charles W.

    Correlations allow us to measure, and quantitatively study, the properties of physical systems, their evolution and their interactions. Quantum discord expresses quantum correlations beyond those associated with entanglement. However, discord has not yet been adopted as a standard subject of study by the experimental community. Here we propose a feasible optical setup to generate symmetric two-qubit X-states with controllable coherences, where the two qubits correspond to the spin and path of a photon. With these states we show how a classical random variable K can be encoded by Alice and decoded by Bob. Using our previous results we study the correlations between the spin and path qubits and its relation with the information about K that can be decoded by Bob using local measurements with or without two-qubit gate operations. Discord is the mutual information contained in the coherences of the system, and it is possible to exploit it for quantum advantage even in the absence of entanglement.

  17. Mean and variance of single photon counting with deadtime

    NASA Astrophysics Data System (ADS)

    Yu, Daniel F.; Fessler, Jeffrey A.

    2000-07-01

    The statistics of photon counting by systems affected by deadtime are potentially important for statistical image reconstruction methods. We present a new way of analysing the moments of the counting process for a counter system affected by various models of deadtime related to PET and SPECT imaging. We derive simple and exact expressions for the first and second moments of the number of recorded events under various models. From our mean expression for a SPECT deadtime model, we derive a simple estimator for the actual intensity of the underlying Poisson process; simulations show that our estimator is unbiased even for extremely high count rates. From this analysis, we study the suitability of the Poisson statistical model assumed in most statistical image reconstruction algorithms. For systems containing `modules' with several detector elements, where each element can cause deadtime losses for the entire module, such as block PET detectors or Anger cameras, the Poisson statistical model appears to be adequate even in the presence of deadtime losses.

  18. Controlling single-photon Fock-state propagation through opaque scattering media

    NASA Astrophysics Data System (ADS)

    Huisman, Thomas J.; Huisman, Simon R.; Mosk, Allard P.; Pinkse, Pepijn W. H.

    2014-09-01

    The control of light scattering is essential in many quantum optical experiments. Wavefront shaping is a technique used for ultimate control over wave propagation through multiple-scattering media by adaptive manipulation of incident waves. We control the propagation of single-photon Fock states through opaque scattering media by spatial phase modulation of the incident wavefront. We enhance the probability that a single photon arrives in a target output mode with a factor 30. Our proof-of-principle experiment shows that the propagation of quantum light through multiple-scattering media can be controlled, with prospective applications in quantum communication and quantum cryptography.

  19. Single-photon pulsed-light indirect time-of-flight 3D ranging.

    PubMed

    Bellisai, S; Bronzi, D; Villa, F A; Tisa, S; Tosi, A; Zappa, F

    2013-02-25

    "Indirect" time-of-flight is one technique to obtain depth-resolved images through active illumination that is becoming more popular in the recent years. Several methods and light timing patterns are used nowadays, aimed at improving measurement precision with smarter algorithms, while using less and less light power. Purpose of this work is to present an indirect time-of-flight imaging camera based on pulsed-light active illumination and a 32 × 32 single-photon avalanche diode array with an improved illumination timing pattern, able to increase depth resolution and to reach single-photon level sensitivity. PMID:23482043

  20. Growth of optical-quality anthracene crystals doped with dibenzoterrylene for controlled single photon production

    SciTech Connect

    Major, Kyle D. Lien, Yu-Hung; Polisseni, Claudio; Grandi, Samuele; Kho, Kiang Wei; Clark, Alex S.; Hwang, J.; Hinds, E. A.

    2015-08-15

    Dibenzoterrylene (DBT) molecules within a crystalline anthracene matrix show promise as quantum emitters for controlled, single photon production. We present the design and construction of a chamber in which we reproducibly grow doped anthracene crystals of optical quality that are several mm across and a few μm thick. We demonstrate control of the DBT concentration over the range 6–300 parts per trillion and show that these DBT molecules are stable single-photon emitters. We interpret our data with a simple model that provides some information on the vapour pressure of DBT.

  1. Active quenching circuit for single-photon detection with Geiger mode avalanche photodiodes.

    PubMed

    Stipcević, Mario

    2009-03-20

    In this paper a novel construction of an active quenching circuit intended for single-photon detection is presented, along with a few original methods for its evaluation. The circuit has been combined with a standard avalanche photodiode C30902S to form a single-photon detector. This detector has a dead time of 39 ns, maximum random counting frequency of 14 MHz, small afterpulsing probability, an estimated peak detection efficiency of over 20%, and a dark count rate of less than 100 Hz. This simple and robust active quenching circuit can be built from off-the-shelf electronic components and is presented with the detailed schematic diagram. PMID:19305468

  2. Generation of a single-photon source via a four-wave mixing process in a cavity

    SciTech Connect

    Fan Bixuan; Duan Zhenglu; Zhou Lu; Yuan Chunhua; Zhang Weiping; Ou, Z. Y.

    2009-12-15

    It is shown that an efficient, well-directional single-photon source can be realized via a four-wave mixing process in a cavity. The probability of producing a single-photon state nearly approaches 50%. The bandwidth of single-photons generated in this way is controllable, which is determined by that of the input pulse. Furthermore, we propose a scheme to generate a coherent multichannel single-photon source, which might have significant applications in wavelength division multiplexing quantum key distribution.

  3. High-Fidelity Down-Conversion Source for Secure Communications Using On-Demand Single Photons

    NASA Technical Reports Server (NTRS)

    Roberts, Tony

    2015-01-01

    AdvR, Inc., has built an efficient, fully integrated, waveguide-based source of spectrally uncorrelated photon pairs that will accelerate research and development (R&D) in the emerging field of quantum information science. Key to the innovation is the use of submicron periodically poled waveguides to produce counter propagating photon pairs, which is enabled by AdvR's patented segmented microelectrode poling technique. This novel device will provide a high brightness source of down-conversion pairs with enhanced spectral properties and low attenuation, and it will operate in the visible to the mid-infrared spectral region. A waveguide-based source of spectrally and spatially pure heralded photons will contribute to a wide range of NASA's advanced technology development efforts, including on-demand single photon sources for high-rate spaced-based secure communications.

  4. Single- and Two-Photon-Induced Processes at the B Factories

    SciTech Connect

    Li, Selina Z.; /SLAC

    2012-06-15

    We discuss single- and two-photon-induced processes in e{sup +}e{sup -} annihilations with center-of-mass energy near 10.58 GeV from the BaBar and Belle experiments. In particular, we present experimental results from two-photon physics of {gamma}{gamma} {yields} {pi}{sup 0}{pi}{sup 0} and {gamma}{gamma}* {yields} {pi}{sup 0}. We also review the observation of the Two-Virtual-Photon-Annihilation process (e{sup +}e{sup -} {yields} {rho}{sup 0}{rho}{sup 0} and e{sup +}e{sup -} {yields} {phi}{rho}{sup 0}) and the observation of e{sup +}e{sup -} {yields} {rho}{sup +}{rho}{sup -}, which should be primarily a one virtual photon process, but whose angular distributions may imply potential interference effects.

  5. Likelihood functions for the analysis of single-molecule binned photon sequences

    PubMed Central

    Gopich, Irina V.

    2011-01-01

    We consider the analysis of a class of experiments in which the number of photons in consecutive time intervals is recorded. Sequence of photon counts or, alternatively, of FRET efficiencies can be studied using likelihood-based methods. For a kinetic model of the conformational dynamics and state-dependent Poisson photon statistics, the formalism to calculate the exact likelihood that this model describes such sequences of photons or FRET efficiencies is developed. Explicit analytic expressions for the likelihood function for a two-state kinetic model are provided. The important special case when conformational dynamics are so slow that at most a single transition occurs in a time bin is considered. By making a series of approximations, we eventually recover the likelihood function used in hidden Markov models. In this way, not only is insight gained into the range of validity of this procedure, but also an improved likelihood function can be obtained. PMID:22711967

  6. The effect of magnetic field on the intrinsic detection efficiency of superconducting single-photon detectors

    SciTech Connect

    Renema, J. J.; Rengelink, R. J.; Komen, I.; Wang, Q.; Kes, P.; Aarts, J.; Exter, M. P. van; Dood, M. J. A. de; Gaudio, R.; Hoog, K. P. M. op 't; Zhou, Z.; Fiore, A.; Sahin, D.; Driessen, E. F. C.

    2015-03-02

    We experimentally investigate the effect of a magnetic field on photon detection in superconducting single-photon detectors (SSPDs). At low fields, the effect of a magnetic field is through the direct modification of the quasiparticle density of states of the superconductor, and magnetic field and bias current are interchangeable, as is expected for homogeneous dirty-limit superconductors. At the field where a first vortex enters the detector, the effect of the magnetic field is reduced, up until the point where the critical current of the detector starts to be determined by flux flow. From this field on, increasing the magnetic field does not alter the detection of photons anymore, whereas it does still change the rate of dark counts. This result points at an intrinsic difference in dark and photon counts, and also shows that no enhancement of the intrinsic detection efficiency of a straight SSPD wire is achievable in a magnetic field.

  7. Slow light generation in single-mode rectangular core photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Yadav, Sandeep; Saini, Than Singh; Kumar, Ajeet

    2016-05-01

    In this paper, we have designed and analyzed a rectangular core photonic crystal fiber (PCF) in Tellurite material. For the designed photonics crystal fiber, we have calculated the values of confinement loss and effective mode area for different values of air filling fraction (d/Λ). For single mode operation of the designed photonic crystal fiber, we have taken d/Λ= 0.4 for the further calculation of stimulated Brillouin scattering based time delay. A maximum time delay of 158 ns has been achieved for input pump power of 39 mW. We feel the detailed theoretical investigations and simulations carried out in the study have the potential impact on the design and development of slow light-based photonic devices.

  8. Traceable calibration of a fibre-coupled superconducting nano-wire single photon detector using characterized synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Müller, Ingmar; Klein, Roman M.; Werner, Lutz

    2014-12-01

    Radiometric calibrations of fibre-coupled single photon detectors are experiencing growing demand, especially at the telecommunication wavelengths. In this paper, the radiometric calibration of a fibre-coupled superconducting nano-wire single photon detector at the telecom wavelength 1.55 µm by means of well-characterized synchrotron radiation is described. This substitution method is based on the unique properties of synchrotron radiation and the Metrology Light Source, the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt, and is suitable for fibre-coupled single photon detectors. The Metrology Light Source is used as a light source with a high dynamic range of the radiant power to bridge the radiometric gap occurring in the transition from radiant power measurements and the counting of photons with single photon detectors. Very low uncertainties below 2% have been achieved in the measurement of the detection efficiency of a fibre-coupled superconducting nano-wire single photon detector.

  9. Photon-energy dependence of single-photon simultaneous core ionization and core excitation in CO2

    NASA Astrophysics Data System (ADS)

    Carniato, S.; Selles, P.; Lablanquie, P.; Palaudoux, J.; Andric, L.; Nakano, M.; Hikosaka, Y.; Ito, K.; Marchenko, T.; Travnikova, O.; Goldsztejn, G.; Journel, L.; Guillemin, R.; Céolin, D.; Simon, M.; Piancastelli, M. N.; Penent, F.

    2016-07-01

    We have studied the K-2V process corresponding to simultaneous K -shell ionization and K -shell excitation in the C O2 molecule. We define these K-2V states as super shake-up, at variance with the "conventional" K-1v-1V shake-up states. While the nature and evolution with photon energy of the conventional shake-up satellites has been the object of many studies, no such data on a large photon-energy range were previously reported on super shake-up. The C O2 molecule is a textbook example because it exhibits two well-isolated K-2V resonances (with V being 2 πu* and 5 σg* ) with different symmetries resulting from shake-up processes of different origin populated in comparable proportions. The variation of the excitation cross section of these two resonances with photon energy is reported, using two different experimental approaches, which sheds light on the excitation mechanisms. Furthermore, double-core-hole spectroscopy is shown to be able to integrate and even expand information provided by conventional single-core-hole X-ray Photoelectron Spectroscopy (XPS) and Near-Edge X-ray Absorption Fine Structure (NEXAFS) techniques, revealing, for instance, g -g dipole forbidden transitions which are only excited in NEXAFS spectra through vibronic coupling.

  10. Superconducting nanowire single-photon detectors integrated with optical nano-antennae

    SciTech Connect

    Hu, X.; Dauler, E.; Molnar, R.; Berggren, K. K.

    2010-12-20

    Optical nano-antennae have been integrated with semiconductor lasers to intensify light at the nanoscale and photodiodes to enhance photocurrent. In quantum optics, plasmonic metal structures have been used to enhance nonclassical light emission from single quantum dots. Absorption and detection of single photons from free space could also be enhanced by nanometallic antennae, but this has not previously been demonstrated. Here, we use nano-optical transmission effects in a one-dimensional gold structure, combined with optical cavity resonance, to form optical nano-antennae, which are further used to couple single photons from free space into a 80-nm-wide superconducting nanowire. This antenna-assisted coupling enables a superconducting nanowire single-photon detector with 47% device efficiency at the wavelength of 1550 nm and 9-μm-by-9-μm active area while maintaining a reset time of only 5 ns. We demonstrate nanoscale antenna-like structures to achieve exceptional efficiency and speed in single-photon detection.

  11. Tuneable on-demand single-photon source in the microwave range.

    PubMed

    Peng, Z H; de Graaf, S E; Tsai, J S; Astafiev, O V

    2016-01-01

    An on-demand single-photon source is a key element in a series of prospective quantum technologies and applications. Here we demonstrate the operation of a tuneable on-demand microwave photon source based on a fully controllable superconducting artificial atom strongly coupled to an open-ended transmission line. The atom emits a photon upon excitation by a short microwave π-pulse applied through a control line. The intrinsically limited device efficiency is estimated to be in the range 65-80% in a wide frequency range from 7.75 to 10.5 GHz continuously tuned by an external magnetic field. The actual demonstrated efficiency is also affected by the excited state preparation, which is about 90% in our experiments. The single-photon generation from the single-photon source is additionally confirmed by anti-bunching in the second-order correlation function. The source may have important applications in quantum communication, quantum information processing and sensing. PMID:27545689

  12. Effect of temperature on superconducting nanowire single-photon detector noise

    NASA Astrophysics Data System (ADS)

    Bahgat Shehata, A.; Ruggeri, A.; Stellari, F.; Weger, Alan J.; Song, P.; Sunter, K.; Najafi, F.; Berggren, Karl K.; Anant, Vikas

    2015-08-01

    Today Superconducting Nanowire Single-Photon Detectors (SNSPDs) are commonly used in different photon-starved applications, including testing and diagnostics of VLSI circuits. Detecting very faint signals in the near-infrared wavelength range requires not only good detection efficiency, but also very low Dark Count Rate (DCR) and jitter. For example, low noise is crucial to enable ultra-low voltage optical testing of integrated circuits. The effect of detector temperature and background thermal radiation on the noise of superconducting single-photon detectors made of NbN meanders is studied in this paper. It is shown that two different regimes can be identified in the DCR vs. bias current characteristics. At high bias, the dark count rate is dominated by the intrinsic noise of the detector, while at low bias current it is dominated by the detection of stray photons that get onto the SNSPD. Changing the detector temperature changes its switching current and only affects the high bias branch of the characteristics: a reduction of the DCR can be achieved by lowering the SNSPD base temperature. On the other hand, changing the temperature of the single-photon light source (e.g. the VLSI circuit under test) only affects the low bias regime: a lower target temperature leads to a smaller DCR.

  13. Tuneable on-demand single-photon source in the microwave range

    PubMed Central

    Peng, Z. H.; de Graaf, S. E.; Tsai, J. S.; Astafiev, O. V.

    2016-01-01

    An on-demand single-photon source is a key element in a series of prospective quantum technologies and applications. Here we demonstrate the operation of a tuneable on-demand microwave photon source based on a fully controllable superconducting artificial atom strongly coupled to an open-ended transmission line. The atom emits a photon upon excitation by a short microwave π-pulse applied through a control line. The intrinsically limited device efficiency is estimated to be in the range 65–80% in a wide frequency range from 7.75 to 10.5 GHz continuously tuned by an external magnetic field. The actual demonstrated efficiency is also affected by the excited state preparation, which is about 90% in our experiments. The single-photon generation from the single-photon source is additionally confirmed by anti-bunching in the second-order correlation function. The source may have important applications in quantum communication, quantum information processing and sensing. PMID:27545689

  14. Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors

    PubMed Central

    Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko

    2015-01-01

    Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks. PMID:26404010

  15. Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors

    NASA Astrophysics Data System (ADS)

    Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko

    2015-09-01

    Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks.

  16. Title: Development of Single photon Quantum Optical Experiments using Type-I and Type-II Spontaneous Parametric Down Conversion

    NASA Astrophysics Data System (ADS)

    Laugharn, Andrew; Maleki, Seyfollah

    We constructed a quantum optical apparatus to control and detect single photons. We generated these photons via Type-I and Type-II spontaneous parametric down conversion by pumping a GaN laser (405nm) incident on a BBO crystal. We detected the two down converted photons (810nm), denoted signal and idler, in coincidence so as to measure and control single photons. We implemented a coincidence counting unite onto an Altera DE2 board and used LabView for data acquisition. We used these photon pairs to demonstrate quantum entanglement and indistinguishability using multiple optical experiments.

  17. New silicon technologies enable high-performance arrays of Single Photon Avalanche Diodes

    PubMed Central

    Gulinatti, Angelo; Rech, Ivan; Maccagnani, Piera; Cova, Sergio; Ghioni, Massimo

    2013-01-01

    In order to fulfill the requirements of many applications, we recently developed a new technology aimed at combining the advantages of traditional thin and thick silicon Single Photon Avalanche Diodes (SPAD). In particular we demonstrated single-pixel detectors with a remarkable improvement in the Photon Detection Efficiency at the longer wavelengths (e.g. 40% at 800nm) while maintaining a timing jitter better than 100ps. In this paper we will analyze the factors the currently prevent the fabrication of arrays of SPADs by adopting such a Red-Enhanced (RE) technology and we will propose further modifications to the device structure that will enable the fabrication of high performance RE-SPAD arrays for photon timing applications. PMID:24353395

  18. Characterization of Terahertz Single-Photon-Sensitive Bolometric Detectors Using a Pulsed Microwave Technique

    SciTech Connect

    Santavicca, D. F.; Frunzio, L.; Prober, D. E.; Reulet, B.; Karasik, B. S.; Pereverzev, S. V.; Olaya, D.; Gershenson, M. E.

    2009-12-16

    We describe a technique for characterizing bolometric detectors that have sufficient sensitivity to count single terahertz photons. The device is isolated from infrared blackbody radiation and a single terahertz photon is simulated by a fast microwave pulse, where the absorbed energy of the pulse is equal to the photon energy. We have employed this technique to characterize bolometric detectors consisting of a superconducting titanium nanobridge with niobium contacts. Present devices have T{sub c} = 0.3 K and a measured intrinsic energy resolution of approximately 6 terahertz full-width at half-maximum, near the predicted value due to intrinsic thermal fluctuation noise, with a time constant of 2 {mu}s. An intrinsic energy resolution of 1 terahertz should be achievable by reducing the volume of the titanium nanobridge. Such a detector has important applications in future space-based terahertz astronomy missions.

  19. Carving complex many-atom entangled states by single-photon detection

    NASA Astrophysics Data System (ADS)

    Hu, Jiazhong; Chen, Wenlan; Duan, Yiheng; Braverman, Boris; Zhang, Hao; Vuletic, Vladan

    We propose a versatile and efficient method to generate a broad class of complex entangled states of many atoms via the detection of a single photon. For an atomic ensemble contained in a strongly coupled optical cavity illuminated by weak single- or multi-frequency light, the atom-light interaction entangles the frequency spectrum of a transmitted photon with the collective spin of the atomic ensemble. Simple time-resolved detection of the transmitted photon then projects the atomic ensemble into a desired pure entangled state. This method can be implemented with existing technology, yields high success probability per trials, and can generate complex entangled states such as multicomponent Schrödinger cat states with high fidelity.

  20. Carving Complex Many-Atom Entangled States by Single-Photon Detection.

    PubMed

    Chen, Wenlan; Hu, Jiazhong; Duan, Yiheng; Braverman, Boris; Zhang, Hao; Vuletić, Vladan

    2015-12-18

    We propose a versatile and efficient method to generate a broad class of complex entangled states of many atoms via the detection of a single photon. For an atomic ensemble contained in a strongly coupled optical cavity illuminated by weak single- or multifrequency light, the atom-light interaction entangles the frequency spectrum of a transmitted photon with the collective spin of the atomic ensemble. Simple time-resolved detection of the transmitted photon then projects the atomic ensemble into a desired pure entangled state. This method can be implemented with existing technology, yields high success probability per trial, and can generate complex entangled states such as mesoscopic superposition states of coherent spin states with high fidelity. PMID:26722909

  1. QUANTUM INFORMATION. Coherent coupling of a single spin to microwave cavity photons.

    PubMed

    Viennot, J J; Dartiailh, M C; Cottet, A; Kontos, T

    2015-07-24

    Electron spins and photons are complementary quantum-mechanical objects that can be used to carry, manipulate, and transform quantum information. To combine these resources, it is desirable to achieve the coherent coupling of a single spin to photons stored in a superconducting resonator. Using a circuit design based on a nanoscale spin valve, we coherently hybridize the individual spin and charge states of a double quantum dot while preserving spin coherence. This scheme allows us to achieve spin-photon coupling up to the megahertz range at the single-spin level. The cooperativity is found to reach 2.3, and the spin coherence time is about 60 nanoseconds. We thereby demonstrate a mesoscopic device suitable for nondestructive spin readout and distant spin coupling. PMID:26206930

  2. Carving Complex Many-Atom Entangled States by Single-Photon Detection

    NASA Astrophysics Data System (ADS)

    Chen, Wenlan; Hu, Jiazhong; Duan, Yiheng; Braverman, Boris; Zhang, Hao; Vuletic, Vladan

    2016-05-01

    We propose a versatile and efficient method to generate a broad class of complex entangled states of many atoms via the detection of a single photon. For an atomic ensemble contained in a strongly coupled optical cavity illuminated by weak single- or multifrequency light, the atom-light interaction entangles the frequency spectrum of a transmitted photon with the collective spin of the atomic ensemble. Simple time-resolved detection of the transmitted photon then projects the atomic ensemble into a desired pure entangled state. This method can be implemented with existing technology, yields high success probability per trial, and can generate complex entangled states such as mesoscopic superposition states of coherent spin states with high fidelity.

  3. Heralded linear optical quantum Fredkin gate based on one auxiliary qubit and one single photon detector

    NASA Astrophysics Data System (ADS)

    Zhu, Chang-Hua; Cao, Xin; Quan, Dong-Xiao; Pei, Chang-Xing

    2014-08-01

    Linear optical quantum Fredkin gate can be applied to quantum computing and quantum multi-user communication networks. In the existing linear optical scheme, two single photon detectors (SPDs) are used to herald the success of the quantum Fredkin gate while they have no photon count. But analysis results show that for non-perfect SPD, the lower the detector efficiency, the higher the heralded success rate by this scheme is. We propose an improved linear optical quantum Fredkin gate by designing a new heralding scheme with an auxiliary qubit and only one SPD, in which the higher the detection efficiency of the heralding detector, the higher the success rate of the gate is. The new heralding scheme can also work efficiently under a non-ideal single photon source. Based on this quantum Fredkin gate, large-scale quantum switching networks can be built. As an example, a quantum Beneš network is shown in which only one SPD is used.

  4. Carving Complex Many-Atom Entangled States by Single-Photon Detection

    NASA Astrophysics Data System (ADS)

    Chen, Wenlan; Hu, Jiazhong; Duan, Yiheng; Braverman, Boris; Zhang, Hao; Vuletić, Vladan

    2015-12-01

    We propose a versatile and efficient method to generate a broad class of complex entangled states of many atoms via the detection of a single photon. For an atomic ensemble contained in a strongly coupled optical cavity illuminated by weak single- or multifrequency light, the atom-light interaction entangles the frequency spectrum of a transmitted photon with the collective spin of the atomic ensemble. Simple time-resolved detection of the transmitted photon then projects the atomic ensemble into a desired pure entangled state. This method can be implemented with existing technology, yields high success probability per trial, and can generate complex entangled states such as mesoscopic superposition states of coherent spin states with high fidelity.

  5. Distillation of arbitrary single-photon entanglement assisted with polarized Bell states

    NASA Astrophysics Data System (ADS)

    Feng, Zhao-Feng; Ou-Yang, Yang; Zhou, Lan; Sheng, Yu-Bo

    2015-10-01

    Single-photon entanglement (SPE) is a promising resource in quantum communication. However, it will suffer from the photon loss. In this paper, we will present an efficient approach to protect the two-mode SPE. This protocol not only can distill the SPE from the mixed state, but also can faithfully protect the information encoded in the polarization degree of freedom. Moreover, different from the previous protocols, if the SPE becomes a less-entangled state, we can also distill it to the maximally entangled state. During the whole protocol, we exploit the polarized Bell states to complete the task. This protocol can also be extended to protect the single-photon multi-mode W state. This protocol is feasible in current technology, for it only requires linear optical elements.

  6. Time-Correlated Single-Photon Counting Range Profiling of Moving Objects

    NASA Astrophysics Data System (ADS)

    Hedborg, Julia; Jonsson, Per; Henriksson, Markus; Sjöqvist, Lars

    2016-06-01

    Time-correlated single-photon counting (TCSPC) is a laser radar technique that can provide range profiling with very high resolution. Range profiles of multiple surface objects and geometrical shapes are revealed using multiple laser pulses with very low pulse energy. The method relies on accurate time measurements between a laser pulse sync signal and the registration of a single-photon event of reflected photons from a target. TCSPC is a statistic method that requires an acquisition time and therefore the range profile of a non-stationary object (target) may be corrupted. Here, we present results showing that it is possible to reconstruct the range profile of a moving target and calculate the velocity of the target.

  7. Hamiltonian of photons in a single-mode optical fiber for quantum communications protocols

    NASA Astrophysics Data System (ADS)

    Miroshnichenko, G. P.

    2012-05-01

    A phenomenological Hamiltonian of photons in a single-mode stochastic inhomogeneous optical fiber (OF) is derived. Quantization of radiation is performed in the basis of an ideal OF with proper calibration that ensures transversality of the electric-field-displacement vector. Stochastic parameters of the Hamiltonian are determined by using the reciprocal tensor of the dielectric permittivity averaged over the OF segment volume. The Hamiltonian is parametrized by three phenomenological parameters and preserves the number of photons. It is assumed that the segment of the OF is divided into random subsegments with optical parameters defined by the Wiener process with respect to the longitudinal coordinate. The temporal dynamics of the single-photon density matrix is analyzed in the basis of states with orthogonal polarizations. The relative quantum beat error rate in the sifted quantum key distributed according to the BB84 protocol with polarization coding of information averaged over the scatter of the OF parameters is calculated.

  8. Single-photon position to time multiplexing using a fiber array.

    PubMed

    Warburton, Ryan E; Izdebski, Frauke; Reimer, Christian; Leach, Jonathan; Ireland, David G; Padgett, Miles; Buller, Gerald S

    2011-01-31

    A 1 x 8 fiber array is used as the front-end of a receiver system. Each channel has a different length of fiber, resulting in each channel signal arriving at the detector at a pre-determined interval relative to a constant repetitive frequency signal. We demonstrate that these eight channels can be efficiently coupled to an individual single-photon detector such that the arrival-time of a photon in each is distinguishable from the next. Thus, we demonstrate spatial position to time information exchange, resulting in a photon-counting array using a single detector. The receiver system could be implemented in numerous applications, including time-resolved photoluminescence, low-light level spectroscopy and quantum information processing. PMID:21369088

  9. Direct generation of genuine single-longitudinal-mode narrowband photon pairs

    NASA Astrophysics Data System (ADS)

    Luo, Kai-Hong; Herrmann, Harald; Krapick, Stephan; Brecht, Benjamin; Ricken, Raimund; Quiring, Viktor; Suche, Hubertus; Sohler, Wolfgang; Silberhorn, Christine

    2015-07-01

    The practical prospect of quantum communication and information processing relies on sophisticated single-photon pairs, which feature a controllable waveform, narrow spectrum, excellent purity, fiber compatibility, and miniaturized design. For practical realizations, stable, miniaturized, low-cost devices are required. Sources with one or some of the above characteristics have already been demonstrated, but it is quite challenging to obtain a source with all of the described characteristics simultaneously. Here we report on an integrated single-longitudinal-mode, non-degenerate, narrowband photon pair source that exhibits all the requirements needed for quantum applications. The device is composed of a periodically poled, Ti-indiffused, lithium niobate waveguide with high reflective dielectric mirror coatings deposited on the waveguide end-faces. Photon pairs with wavelengths around 890 and 1320 nm are generated via type II phase-matched parametric down-conversion (PDC). Clustering in this dispersive cavity restricts the whole conversion spectrum to one single-longitudinal mode in a single cluster, yielding a narrow bandwidth of only 60 MHz. The high conversion efficiency in the waveguide, together with the spectral clustering in the doubly resonant waveguide, leads to a high brightness of 3× {10}4 pairs/(s mW MHz). This source exhibits prominent single-longitudinal-mode purity and remarkable temporal shaping capability. In particular, due to temporal broadening, we can observe that the coherence time of the two-photon component of the PDC state is actually longer than that of the single-photon states. The miniaturized monolithic design enables this source to have various fiber communication applications.

  10. Bright single-photon sources in bottom-up tailored nanowires

    PubMed Central

    Reimer, Michael E.; Bulgarini, Gabriele; Akopian, Nika; Hocevar, Moïra; Bavinck, Maaike Bouwes; Verheijen, Marcel A.; Bakkers, Erik P.A.M.; Kouwenhoven, Leo P.; Zwiller, Val

    2012-01-01

    The ability to achieve near-unity light-extraction efficiency is necessary for a truly deterministic single-photon source. The most promising method to reach such high efficiencies is based on embedding single-photon emitters in tapered photonic waveguides defined by top-down etching techniques. However, light-extraction efficiencies in current top-down approaches are limited by fabrication imperfections and etching-induced defects. The efficiency is further tempered by randomly positioned off-axis quantum emitters. Here we present perfectly positioned single quantum dots on the axis of a tailored nanowire waveguide using bottom-up growth. In comparison to quantum dots in nanowires without waveguides, we demonstrate a 24-fold enhancement in the single-photon flux, corresponding to a light-extraction efficiency of 42%. Such high efficiencies in one-dimensional nanowires are promising to transfer quantum information over large distances between remote stationary qubits using flying qubits within the same nanowire p–n junction. PMID:22415828

  11. A near-infrared 64-pixel superconducting nanowire single photon detector array with integrated multiplexed readout

    SciTech Connect

    Allman, M. S. Verma, V. B.; Stevens, M.; Gerrits, T.; Horansky, R. D.; Lita, A. E.; Mirin, R.; Nam, S. W.; Marsili, F.; Beyer, A.; Shaw, M. D.; Kumor, D.

    2015-05-11

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array as well as characterization measurements are discussed.

  12. Quantum teleportation of the angular spectrum of a single-photon field

    SciTech Connect

    Walborn, S. P.; Ether, D. S.; Matos Filho, R. L. de; Zagury, N.

    2007-09-15

    We propose a quantum teleportation scheme for the angular spectrum of a single-photon field, which allows for the transmission of a large amount of information. Our proposal also provides a method to tune the frequencies of spatially entangled fields, which is useful for interactions with stationary qubits.

  13. Revisiting single photon avalanche diode current-voltage modeling and transient characteristics

    SciTech Connect

    Javitt, M.; Savuskan, V. Merhav, T.; Nemirovsky, Y.

    2014-05-28

    A model for the current-voltage and transient behavior of Single Photon Avalanche Diodes (SPADs) based on device physics is presented. The results of the model are compared to actual measurements and a reasonable fit is seen. Additionally, the model provides a useful tool for designing quenching circuitry and determining optimal operation conditions of the SPAD.

  14. Location of the lowest exciton in C 60 single crystal by two-photon excitation spectroscopy

    NASA Astrophysics Data System (ADS)

    Muccini, M.; Danieli, R.; Zamboni, R.; Taliani, C.; Mohn, H.; Müller, W.; ter Meer, H. U.

    1995-10-01

    Two-photon excitation of C 60 single crystal at 4 K shows a sharp band at 1.846 eV which is assigned to the lowest forbidden Frenkel singlet exciton of T 1g symmetry. This assignment is supported by the analysis of Herzberg-Teller induced photoluminescence.

  15. Characterizing time decay of bibenzyl scintillator using time correlated single photon counting.

    PubMed

    Hatarik, R; Bernstein, L A; Caggiano, J A; Carman, M L; Schneider, D H G; Zaitseva, N P; Wiedeking, M

    2012-10-01

    The time decay of several scintillation materials has been measured using the time correlated single photon counting method and a new organic crystal with a highly suppressed delayed light has been identified. Results comparing the light decay of the bibenzyl crystal with a xylene based detector, which is currently installed at National Ignition Facility will be presented. PMID:23126914

  16. Characterizing time decay of bibenzyl scintillator using time correlated single photon countinga)

    NASA Astrophysics Data System (ADS)

    Hatarik, R.; Bernstein, L. A.; Caggiano, J. A.; Carman, M. L.; Schneider, D. H. G.; Zaitseva, N. P.; Wiedeking, M.

    2012-10-01

    The time decay of several scintillation materials has been measured using the time correlated single photon counting method and a new organic crystal with a highly suppressed delayed light has been identified. Results comparing the light decay of the bibenzyl crystal with a xylene based detector, which is currently installed at National Ignition Facility will be presented.

  17. Characterizing time decay of bibenzyl scintillator using time correlated single photon counting

    SciTech Connect

    Hatarik, R.; Bernstein, L. A.; Caggiano, J. A.; Carman, M. L.; Schneider, D. H. G.; Zaitseva, N. P.; Wiedeking, M.

    2012-10-15

    The time decay of several scintillation materials has been measured using the time correlated single photon counting method and a new organic crystal with a highly suppressed delayed light has been identified. Results comparing the light decay of the bibenzyl crystal with a xylene based detector, which is currently installed at National Ignition Facility will be presented.

  18. Optical Field-Strength Polarization of Two-Mode Single-Photon States

    ERIC Educational Resources Information Center

    Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

  19. Dinuclear ruthenium(II) polypyridyl complexes as single and two-photon luminescence cellular imaging probes.

    PubMed

    Xu, Wenchao; Zuo, Jiarui; Wang, Lili; Ji, Liangnian; Chao, Hui

    2014-02-28

    A new series of dinuclear ruthenium(II) polypyridyl complexes, which possess larger π-conjugated systems, good water solubility and pH resistance, and high photostability, were developed to act as single and two-photon luminescence cellular imaging probes. PMID:24418839

  20. Faint laser pulses versus a single-photon source in free space quantum cryptography

    NASA Astrophysics Data System (ADS)

    Molotkov, S. N.; Potapova, T. A.

    2016-03-01

    In this letter we present estimates for the distance of secret key transmission through free space for three different protocols of quantum key distribution: for BB84 and phase time-coding protocols in the case of a strictly single-photon source, and for the relativistic quantum key distribution protocol in the case of faint laser pulses.

  1. Novel approaches to power scaling of single-frequency photonic crystal fiber amplifiers

    NASA Astrophysics Data System (ADS)

    Robin, Craig Andrew

    This dissertation presents experimental and theoretical studies of high power, single-frequency, ytterbium-doped photonic crystal fiber amplifiers. The objective of this effort is to identify issues which limit power scaling and develop novel techniques to overcome these limitations. Historically, stimulated Brillouin scattering (SBS) has been the primary obstacle in the realization of high power single-frequency fiber amplifiers. A novel acoustically tailored photonic crystal fiber design, having a reduced Brillouin gain coefficient of 1.2x10-11 m/W, is demonstrated. The fiber design is such that it may be used in conjunction with other SBS mitigation techniques, which increases the nonlinear threshold beyond the current state of the art. In the successful suppression of SBS, a new regime of single-frequency photonic crystal fiber amplifier power scaling is explored. Instabilities in the transverse mode is observed at increasing output powers. Mitigation of this effect is demonstrated experimentally. This empirical data is used as the basis for a theoretical treatment of the problem, which provides direction for future fiber amplifier designs. The culmination of this work results in the successful utilization of the acoustically tailored photonic crystal fiber in a single-frequency counter-pumped amplifier configuration, yielding close to 500 W output power and near diffraction-limited beam quality.

  2. Single-photon sensitive Geiger-mode LADAR cameras

    NASA Astrophysics Data System (ADS)

    Yuan, Ping; Sudharsanan, Rengarajan; Bai, Xiaogang; McDonald, Paul; Labios, Eduardo; Morris, Bryan; Nicholson, John P.; Stuart, Gary M.; Danny, Harrison

    2012-10-01

    Three-dimensional (3D) imaging with Short wavelength infrared (SWIR) Laser Detection and Range (LADAR) systems have been successfully demonstrated on various platforms. It has been quickly adopted in many military and civilian applications. In order to minimize the LADAR system size, weight, and power (SWAP), it is highly desirable to maximize the camera sensitivity. Recently Spectrolab has demonstrated a compact 32x32 LADAR camera with single photo-level sensitivity at 1064. This camera has many special features such as non-uniform bias correction, variable range gate width from 2 microseconds to 6 microseconds, windowing for smaller arrays, and short pixel protection. Boeing integrated this camera with a 1.06 μm pulse laser on various platforms and demonstrated 3D imaging. The features and recent test results of the 32x128 camera under development will be introduced.

  3. Photonic single nonlinear-delay dynamical node for information processing

    NASA Astrophysics Data System (ADS)

    Ortín, Silvia; San-Martín, Daniel; Pesquera, Luis; Gutiérrez, José Manuel

    2012-06-01

    An electro-optical system with a delay loop based on semiconductor lasers is investigated for information processing by performing numerical simulations. This system can replace a complex network of many nonlinear elements for the implementation of Reservoir Computing. We show that a single nonlinear-delay dynamical system has the basic properties to perform as reservoir: short-term memory and separation property. The computing performance of this system is evaluated for two prediction tasks: Lorenz chaotic time series and nonlinear auto-regressive moving average (NARMA) model. We sweep the parameters of the system to find the best performance. The results achieved for the Lorenz and the NARMA-10 tasks are comparable to those obtained by other machine learning methods.

  4. Single Cesium Lead Halide Perovskite Nanocrystals at Low Temperature: Fast Single-Photon Emission, Reduced Blinking, and Exciton Fine Structure

    PubMed Central

    2016-01-01

    Metal-halide semiconductors with perovskite crystal structure are attractive due to their facile solution processability, and have recently been harnessed very successfully for high-efficiency photovoltaics and bright light sources. Here, we show that at low temperature single colloidal cesium lead halide (CsPbX3, where X = Cl/Br) nanocrystals exhibit stable, narrow-band emission with suppressed blinking and small spectral diffusion. Photon antibunching demonstrates unambiguously nonclassical single-photon emission with radiative decay on the order of 250 ps, representing a significant acceleration compared to other common quantum emitters. High-resolution spectroscopy provides insight into the complex nature of the emission process such as the fine structure and charged exciton dynamics. PMID:26771336

  5. Silicon photon-counting avalanche diodes for single-molecule fluorescence spectroscopy

    PubMed Central

    Michalet, Xavier; Ingargiola, Antonino; Colyer, Ryan A.; Scalia, Giuseppe; Weiss, Shimon; Maccagnani, Piera; Gulinatti, Angelo; Rech, Ivan; Ghioni, Massimo

    2014-01-01

    Solution-based single-molecule fluorescence spectroscopy is a powerful experimental tool with applications in cell biology, biochemistry and biophysics. The basic feature of this technique is to excite and collect light from a very small volume and work in a low concentration regime resulting in rare burst-like events corresponding to the transit of a single molecule. Detecting photon bursts is a challenging task: the small number of emitted photons in each burst calls for high detector sensitivity. Bursts are very brief, requiring detectors with fast response time and capable of sustaining high count rates. Finally, many bursts need to be accumulated to achieve proper statistical accuracy, resulting in long measurement time unless parallelization strategies are implemented to speed up data acquisition. In this paper we will show that silicon single-photon avalanche diodes (SPADs) best meet the needs of single-molecule detection. We will review the key SPAD parameters and highlight the issues to be addressed in their design, fabrication and operation. After surveying the state-of-the-art SPAD technologies, we will describe our recent progress towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. The potential of this approach is illustrated with single-molecule Förster resonance energy transfer measurements. PMID:25309114

  6. Development of new photon-counting detectors for single-molecule fluorescence microscopy

    PubMed Central

    Michalet, X.; Colyer, R. A.; Scalia, G.; Ingargiola, A.; Lin, R.; Millaud, J. E.; Weiss, S.; Siegmund, Oswald H. W.; Tremsin, Anton S.; Vallerga, John V.; Cheng, A.; Levi, M.; Aharoni, D.; Arisaka, K.; Villa, F.; Guerrieri, F.; Panzeri, F.; Rech, I.; Gulinatti, A.; Zappa, F.; Ghioni, M.; Cova, S.

    2013-01-01

    Two optical configurations are commonly used in single-molecule fluorescence microscopy: point-like excitation and detection to study freely diffusing molecules, and wide field illumination and detection to study surface immobilized or slowly diffusing molecules. Both approaches have common features, but also differ in significant aspects. In particular, they use different detectors, which share some requirements but also have major technical differences. Currently, two types of detectors best fulfil the needs of each approach: single-photon-counting avalanche diodes (SPADs) for point-like detection, and electron-multiplying charge-coupled devices (EMCCDs) for wide field detection. However, there is room for improvements in both cases. The first configuration suffers from low throughput owing to the analysis of data from a single location. The second, on the other hand, is limited to relatively low frame rates and loses the benefit of single-photon-counting approaches. During the past few years, new developments in point-like and wide field detectors have started addressing some of these issues. Here, we describe our recent progresses towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. We also discuss our development of large area photon-counting cameras achieving subnanosecond resolution for fluorescence lifetime imaging applications at the single-molecule level. PMID:23267185

  7. Silicon photon-counting avalanche diodes for single-molecule fluorescence spectroscopy.

    PubMed

    Michalet, Xavier; Ingargiola, Antonino; Colyer, Ryan A; Scalia, Giuseppe; Weiss, Shimon; Maccagnani, Piera; Gulinatti, Angelo; Rech, Ivan; Ghioni, Massimo

    2014-11-01

    Solution-based single-molecule fluorescence spectroscopy is a powerful experimental tool with applications in cell biology, biochemistry and biophysics. The basic feature of this technique is to excite and collect light from a very small volume and work in a low concentration regime resulting in rare burst-like events corresponding to the transit of a single molecule. Detecting photon bursts is a challenging task: the small number of emitted photons in each burst calls for high detector sensitivity. Bursts are very brief, requiring detectors with fast response time and capable of sustaining high count rates. Finally, many bursts need to be accumulated to achieve proper statistical accuracy, resulting in long measurement time unless parallelization strategies are implemented to speed up data acquisition. In this paper we will show that silicon single-photon avalanche diodes (SPADs) best meet the needs of single-molecule detection. We will review the key SPAD parameters and highlight the issues to be addressed in their design, fabrication and operation. After surveying the state-of-the-art SPAD technologies, we will describe our recent progress towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. The potential of this approach is illustrated with single-molecule Förster resonance energy transfer measurements. PMID:25309114

  8. Ultrafast Room-Temperature Single Photon Emission from Quantum Dots Coupled to Plasmonic Nanocavities.

    PubMed

    Hoang, Thang B; Akselrod, Gleb M; Mikkelsen, Maiken H

    2016-01-13

    Efficient and bright single photon sources at room temperature are critical components for quantum information systems such as quantum key distribution, quantum state teleportation, and quantum computation. However, the intrinsic radiative lifetime of quantum emitters is typically ∼10 ns, which severely limits the maximum single photon emission rate and thus entanglement rates. Here, we demonstrate the regime of ultrafast spontaneous emission (∼10 ps) from a single quantum emitter coupled to a plasmonic nanocavity at room temperature. The nanocavity integrated with a single colloidal semiconductor quantum dot produces a 540-fold decrease in the emission lifetime and a simultaneous 1900-fold increase in the total emission intensity. At the same time, the nanocavity acts as a highly efficient optical antenna directing the emission into a single lobe normal to the surface. This plasmonic platform is a versatile geometry into which a variety of other quantum emitters, such as crystal color centers, can be integrated for directional, room-temperature single photon emission rates exceeding 80 GHz. PMID:26606001

  9. Spectral-hole memory for light at the single-photon level

    NASA Astrophysics Data System (ADS)

    Kutluer, Kutlu; Pascual-Winter, María Florencia; Dajczgewand, Julian; Ledingham, Patrick M.; Mazzera, Margherita; Chanelière, Thierry; de Riedmatten, Hugues

    2016-04-01

    We demonstrate a solid-state spin-wave optical memory based on stopped light in a spectral hole. A long-lived narrow spectral hole is created by optical pumping in the inhomogeneous absorption profile of a Pr3 +:Y2SiO5 crystal. Optical pulses sent through the spectral hole experience a strong reduction of their group velocity and are spatially compressed in the crystal. A short Raman pulse transfers the optical excitation to the spin state before the light pulse exits the crystal, effectively stopping the light. After a controllable delay, a second Raman pulse is sent, which leads to the emission of the stored photons. We reach storage and retrieval efficiencies for bright pulses of up to 39 % in a 5-mm-long crystal. We also show that our device works at the single-photon level by storing and retrieving 3 -μ s -long weak coherent pulses with efficiencies up to 31 % , demonstrating the most efficient spin-wave solid-state optical memory at the single-photon level so far. We reach an unconditional noise level of (9 ±1 ) ×10-3 photons per pulse in a detection window of 4 μ s , leading to a signal-to-noise ratio of 33 ±4 for an average input photon number of 1, making our device promising for long-lived storage of nonclassical light.

  10. Deterministic reshaping of single-photon spectra using cross-phase modulation

    PubMed Central

    Matsuda, Nobuyuki

    2016-01-01

    The frequency conversion of light has proved to be a crucial technology for communication, spectroscopy, imaging, and signal processing. In the quantum regime, it also offers great potential for realizing quantum networks incorporating disparate physical systems and quantum-enhanced information processing over a large computational space. The frequency conversion of quantum light, such as single photons, has been extensively investigated for the last two decades using all-optical frequency mixing, with the ultimate goal of realizing lossless and noiseless conversion. I demonstrate another route to this target using frequency conversion induced by cross-phase modulation in a dispersion-managed photonic crystal fiber. Owing to the deterministic and all-optical nature of the process, the lossless and low-noise spectral reshaping of a single-photon wave packet in the telecommunication band has been readily achieved with a modulation bandwidth as large as 0.4 THz. I further demonstrate that the scheme is applicable to manipulations of a nonclassical frequency correlation, wave packet interference, and entanglement between two photons. This approach presents a new coherent frequency interface for photons for quantum information processing. PMID:27051862

  11. Deterministic reshaping of single-photon spectra using cross-phase modulation.

    PubMed

    Matsuda, Nobuyuki

    2016-03-01

    The frequency conversion of light has proved to be a crucial technology for communication, spectroscopy, imaging, and signal processing. In the quantum regime, it also offers great potential for realizing quantum networks incorporating disparate physical systems and quantum-enhanced information processing over a large computational space. The frequency conversion of quantum light, such as single photons, has been extensively investigated for the last two decades using all-optical frequency mixing, with the ultimate goal of realizing lossless and noiseless conversion. I demonstrate another route to this target using frequency conversion induced by cross-phase modulation in a dispersion-managed photonic crystal fiber. Owing to the deterministic and all-optical nature of the process, the lossless and low-noise spectral reshaping of a single-photon wave packet in the telecommunication band has been readily achieved with a modulation bandwidth as large as 0.4 THz. I further demonstrate that the scheme is applicable to manipulations of a nonclassical frequency correlation, wave packet interference, and entanglement between two photons. This approach presents a new coherent frequency interface for photons for quantum information processing. PMID:27051862

  12. Octave-spanning spectral phase control for single-cycle bi-photons

    NASA Astrophysics Data System (ADS)

    Shaked, Yaakov; Yefet, Shai; Geller, Tzahi; Pe'er, Avi

    2015-07-01

    The quantum correlation of octave-spanning time-energy entangled bi-photons can be as short as a single optical cycle. Many experiments designed to explore and exploit this correlation require a uniform spectral phase (transform-limited) with very low loss. So far, transform-limited single-cycle bi-photons have not been demonstrated, primarily due to the lack of precise, broadband control of their spectral phase. Here, we demonstrate the correction of the spectral-phase of near-octave spanning bi-photons to \\varphi \\lt π /20 over an octave in frequency ≈ 1330-2600 nm). Using a prism-pair with an effectively negative separation for shaping the bi-photons’ spectral phase, we obtain a tuned, very low-loss compensation of both the second and fourth dispersion orders. An essential requisite for precise tuning over such a broad bandwidth is a measure of the spectral phase that provides feedback for the tuning even when the overall dispersion is far from compensated. This is achieved by a non-classical bi-photon interference, which enables direct verification of the corrected bi-photon spectral phase.

  13. Classes of two-photon states defined by linear interactions and destructive two-photon quantum interference in a single mode

    NASA Astrophysics Data System (ADS)

    Lund, A. P.

    2015-11-01

    We describe a two-photon quantum interference effect which differs from the Hong-Ou-Mandel effect in that the destructive quantum inference occurs on a component of the state where two photons are in a single output mode while maintaining the two-photon events in the alternative mode. This effect is manifestly nonclassical but requires more sophisticated technology to observe than the Hong-Ou-Mandel effect. The theory outlined in this paper can also be used to classify two-photon states into classes which are related by the ability to transform the states within the class by using only linear optical interactions. This theory shows that there is an infinite number of these classes of two photon states when there are two or more modes which can support the photons.

  14. Non-blinking single-photon generation with anisotropic colloidal nanocrystals: towards room-temperature, efficient, colloidal quantum sources.

    PubMed

    Pisanello, Ferruccio; Leménager, Godefroy; Martiradonna, Luigi; Carbone, Luigi; Vezzoli, Stefano; Desfonds, Pascal; Cozzoli, Pantaleo Davide; Hermier, Jean-Pierre; Giacobino, Elisabeth; Cingolani, Roberto; De Vittorio, Massimo; Bramati, Alberto

    2013-04-11

    Blinking and single-photon emission can be tailored in CdSe/CdS core/shell colloidal dot-in-rods. By increasing the shell thickness it is possible to obtain almost non-blinking nanocrystals, while the shell length can be used to control single-photon emission probability. PMID:23334905

  15. Radio frequency phototube and optical clock: High resolution, high rate and highly stable single photon timing technique

    SciTech Connect

    Margaryan, Amur

    2011-10-01

    A new timing technique for single photons based on the radio frequency phototube and optical clock or femtosecond optical frequency comb generator is proposed. The technique has a 20 ps resolution for single photons, is capable of operating with MHz frequencies and achieving 10 fs instability level.

  16. Sufficient condition for the mode mismatch of single photons for scalability of the boson-sampling computer

    NASA Astrophysics Data System (ADS)

    Shchesnovich, V. S.

    2014-02-01

    The boson sampler proposed by Aaronson and Arkhipov is a nonuniversal quantum computer, which can serve as evidence against the extended Church-Turing thesis. It samples the probability distribution at the output of a linear unitary optical network with indistinguishable single photons at the input. Four experimental groups have already tested their small-scale prototypes with up to four photons. A boson sampler with a few dozens of single photons is believed to be hard to simulate on a classical computer. For scalability of a realistic boson sampler with current technology it is necessary to know the effect of the photon mode mismatch on its operation. Here a nondeterministic model of the boson sampler is analyzed, which employs partially indistinguishable single photons emitted by identical sources. A sufficient condition on the average mutual fidelity of the single photons is found, which guarantees that the realistic boson sampler outperforms the classical computer. Moreover, the boson-sampler computer with partially indistinguishable single photons is scalable and has more power than classical computers when the single-photon mode mismatch 1- scales as O (N-3/2) with the total number of photons N.

  17. Multiparty quantum sealed-bid auction using single photons as message carrier

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Jie; Wang, Hai-Bin; Yuan, Gong-Lin; Xu, Yong; Chen, Zhen-Yu; An, Xing-Xing; Ji, Fu-Gao; Gnitou, Gnim Tchalim

    2016-02-01

    In this study, a novel multiparty quantum sealed-bid auction protocol using the single photons as the message carrier of bids is proposed, followed by an example of three-party auction. Compared with those protocols based on the entangled states (GHZ state, EPR pairs, etc.), the present protocol is more economic and feasible within present technology. In order to guarantee the security and the fairness of the auction, the decoy photon checking technique and an improved post-confirmation mechanism with EPR pairs are introduced, respectively.

  18. Experimental observation of simultaneous wave and particle behavior in a narrowband single-photon wave packet

    NASA Astrophysics Data System (ADS)

    Yan, Hui; Liao, Kaiyu; Deng, Zhitao; He, Junyu; Xue, Zheng-Yuan; Zhang, Zhi-Ming; Zhu, Shi-Liang

    2015-04-01

    Light's wave-particle duality is at the heart of quantum mechanics and can be well illustrated by Wheeler's delayed-choice experiment: The choice of inserting or removing the second classical (quantum) beam splitter in a Mach-Zehnder interferometer determines the classical (quantum) wave-particle behavior of a photon. In this paper, we report our experiment on directly observing simultaneous wave and particle behavior in a narrowband single-photon wave packet by classically inserting or removing the second beam splitter when part of the wave packet passes through it. Our experiment demonstrates that the produced wave-particle state can be utilized in encoding quantum information.

  19. Long-range interactions and entanglement of slow single-photon pulses

    SciTech Connect

    Friedler, Inbal; Kurizki, Gershon; Petrosyan, David; Fleischhauer, Michael

    2005-10-15

    We show that very large nonlocal nonlinear interactions between pairs of colliding slow-light pulses can be realized in atomic vapors in the regime of electromagnetically induced transparency. These nonlinearities are mediated by strong, long-range dipole-dipole interactions between Rydberg states of the multilevel atoms in a ladder configuration. In contrast to previously studied schemes, this mechanism can yield a homogeneous conditional phase shift of {pi} even for weakly focused single-photon pulses, thereby allowing a deterministic realization of the photonic phase gate.

  20. Measurement of the atom number distribution in an optical tweezer using single-photon counting

    SciTech Connect

    Fuhrmanek, A.; Sortais, Y. R. P.; Grangier, P.; Browaeys, A.

    2010-08-15

    We demonstrate in this paper a method to reconstruct the atom number distribution of a cloud containing a few tens of cold atoms. The atoms are first loaded from a magneto-optical trap into a microscopic optical dipole trap and then released in a resonant light probe where they undergo a Brownian motion and scatter photons. We count the number of photon events detected on an image intensifier. Using the response of our detection system to a single atom as a calibration, we extract the atom number distribution when the trap is loaded with more than one atom. The atom number distribution is found to be compatible with a Poisson distribution.